It's worth it if you can find the right niche and stick to very small projects. I do a few hours writing code for people all over the world (my most frequent client is in Dubai) each week that works out to around $40-$60/hour and it's fun. Larger projects come in closer to $100/hour.

It's the kind of thing I'd be doing as a hobby anyway, but I get paid for it.

Hint: avoid the freelancer sites and instead hang out on developer/hobby code sites. You'll soon see that there are a fair number of people asking for help and are willing to pay, but most of the experienced developers just make fun of them. That's your opportunity! It's amazing how much money you can make by just being nice.