If your muscles and tendons are struggling, the last thing they need is more to do. I would strongly recommend doing whatever you can to give your hands a break for a while, and then start strengthening. And for giving your hands a break, you should absolutely feel justified in getting whatever ergonomic gadgets you think will help.
If you are suffering from numbness, that means your nerves (ulnar nerve, etc) are irritated. There are indications that this is not just a hand problem, but is due to postural problems in the upper back and neck from sitting statically in front of the computer for long hours. Google "thorassic outlet syndrome".
I highly recommend you check out the following books:
"It's not Carpal Tunnel Syndrome", http://www.amazon.com/Carpal-Syndrome-Therapy-Computer-Profe...
"Trigger point therapy workbook", http://www.amazon.com/Trigger-Point-Therapy-Workbook-Self-Tr...
I give these books a lot of credit for my almost complete recovery.
Trigger point therapy is worth looking into...
but try not to get caught up in the hype of gadgets. pushup bars and ab-machines usually just collect dust. jogging, crunches, and pushups are fine. If there's a college nearby, grab your sweats and run their stadium on the weekends.
also-- crossfit.com has a new workout everyday which is short and intense. good if you don't have very much time.
rock climbing is also fun, great for your hands, and a good way to meet cool people.
along these lines, the best workout is the one you don't notice. you'll run more in a pickup soccer game and have more fun than if you go out for a jog.
Paying attention to your body is much closer to the problem than gadgets - but I believe that "work out" often isn't close enough. For every story of "working out" helping someone, I suspect you will find a couple stories of it injuring someone. Sadly, normal computer use general involves considerable insult to the proper use of your body. Putting further strain on your arms and legs through weights and other devices has often resulted in a further problems for people.
Certainly there are some bodies that are helped by this - one must always keep in mind how much variation in bodies there is in we biological humans and not assume one person's solution will automatically work for another person, meaning you.
That said, what I'd strong suggest is that you need is to become aware of the proper use of your own body. One good resource for this: "The Alexander Technique". Another: qigong in general and http://www.qidao.org in particular. Yoga has helped some though I'm dubious - Yoga is also more harsh disciple, people say good things about Feldenkrais. Another very good thing to try is Tai Chi. There various solutions out there aren't mutually exclusive but approaches that are gentle and gradual tend to be best in my opinion. Gentle and gradual - if nothing else, remember that.
I found that regular mice gave me a lot of wrist problems after years of playing FPS games with a "death grip." I use trackballs and trackpads now. I understand that other people have trouble with trackpads so YMMV.
I have similar wrist pain that comes and goes, and when it gets bad I just take it easy and make sure to drink a lot of water and that tends to ease the pain.
Also taking over the counter anti-inflammatories can help in the interim period until you gain some wrist strength. I don't take any drugs regularly, and I notice that 2 ibuprofen in the morning usually takes care of it for 24 hours. Obviously you're not going to want to take them every day for a long time :)
Lastly try to pay attention to what you do with your hands when you sleep. If you tend to curl your fingers under your pillow or something it can make the muscles cramp up overnight and make the pain worse.
You could also see a physiotherapist.
A good one will give you exercises you can do to strengthen the muscles in your wrist. Mine gave me things I can do while I'm sitting in my chair thinking, or just on a quick break while still in the office.
Anyway, I agree with the parent: gadgets might help, but the real fix is likely exercise.
It's possible that different underlying issues alter the effectiveness, but I think the general advice of "exercise" is a good one. I'd also add that there's potential to hurt yourself more, so I'd rewrite the parent comment as "you should also see a physiotherapist."
Take a broom handle and just rotate it in your hands for a minute. Add a string on that and a _small_ weight, and continue adding weight slowly (rolling the weight up to the bar and then back down). (edit: slowly being weekly)
Squeeze a stress ball for a solid 5 minute session in the morning.
Pushup type motions focusing on rotating through wrist angles once you are able.
I would recommend these to the healthy - if you are severely injured go to a doctor and get better first.
I used to work out a while back, 3 to 4 times per week, and one of the things that made me stop (besides boredom to be frank) was that I felt quite a bit of pain in the wrists. I've kept that exercising schedule for 4 months at a time, but the pain didn't go away in those periods. My thought was that I was damaging my wrists in some way.
How long was it until you stopped feeling numb? Did you use any restraining device (gloves or something like that) while working out?
But I have absolutely no problem doing barbell or dumbbell exercises where I have control over the angles. I would suggest to anyone starting out to avoid machines if at all possible.
One of the major things I notice when my wrists start getting irritated is that if I sit up straighter it helps. There are nerves running from thumbs to mid-back, and posture affects them immensely. Simply sitting correctly may (or may not, depending on how bad you habitually sit) be easier than exercise and provide more immediate remedy.
Still, exercise. Definitely.
Specifically, rock climbing absolutely puts your wrists through the gamut. The strength and flexibility building you'll go through will demolish RSI.
When I had problems with my wrists, I started to play the piano, a lot. I would bang on the keys fortzando and make a lot of noise (the noise got better over time :).
I also had a small stress ball that I would squeeze as hard as I could several times throughout the day.
After two or three months, the pain, numbness, and swelling were gone, and have never come back these last dozen years.
You need to work out.
Over a year ago, I was starting to get the beginning stages of RSI. I smoke and was really overweight. I had never been to a gym.
The thing that fixed my wrists was pushing weights. Putting aside the other workout stuff I do (biking, rowing, and moderate running) because they don't pertain to this discussion, moderate weight lifting is key.
The muscles and tendons in your wrist are weak. Mine certainly were. Adding to that the 8-10 hours a day of keyboard typing, you develop RSI.
When I started using weight machines, my wrists were numb and I had flexibility problems. Simply using upper-body weight machines for several months quickly helped to increase my upper body strength, but more importantly let my wrists develop strength they didn't have before. Ever since my wrist problems have completely vanished.
So yes, ergonomic keyboards are definitely useful, even though I don't personally use one. The text editor you're using has absolutely to fucking do with problems with your wrists. Get an ergo keyboard if you feel like it. It won't hurt and will probably help.
However, if you absolutely want to solve your pain you need to work out. Pushups and upper-body workouts are what you need. No body-building crazy shit, just moderate strength training 2-4 times a week for a half an hour at a time.
On the broader workout subject, weight lifting is the fun part of the workout for me. The biking/rowing bit are just tedious calorie burners. When you lift the weights, you're immediately releasing endorphins into your system. So after a good session, you actually feel good.