If anyone here is using DD-WRT, take a look at these instructions before trying to set up your freedns subdomain (needs a token instead of login/password): extracted from http://www.dd-wrt.com/wiki/index.php/DDNS_-_How_to_setup_Cus...
Go to http://freedns.afraid.org/dynamic/ and login with your normal username and password for the freedns service. Click "Direct URL" on the domain you would like to be set to your WAN IP address. Copy everything from the right of the ? in the address bar.
Router Settings: DDNS Service: freedns.afraid.org User Name: USERNAME Password: PASSWORD Host Name: yourdomain.com,What_You_Copied_Before Force Update Interval 10
(Note: Since afraid.org doesn't require a username and password when doing a "wget-style" update, you can also just do the following to keep from exposing your username and password: User Name: guest Password: guest)
I've been happily using it for years, and Josh is very responsive if you have problems or questions.
Mostly because 1. it's free and 2. it was one of the listed providers supported by my OpenWRT router[1].
While I'm not against paying for services per se, I didn't really feel like one simple host was worth shelling out $20 for on an annual, perpetual basis.
I think that the offering when I signed up was two free zones. Now it looks like you can get one for free, unless I'm just grandfathered in.
Oh, well. Time to move on.