We use everydns.com here as well. It is free, but they do ask for donations. If you donate I think it is at least $15 they will remove the restrictions on the number of domains you have. They have an easy to use web interface and are extremely reliable. Overall we couldn't be happier with them.
Thank you guys, I'll try it out
I use everydns as well, and donated, but never got credit for it. Though I'm happy I donated and still like the service.
I'm also a fan and user of everydns. I tried running my own DNS server, but the assorted annoyances got the better of me.