My good old and short dynamic domain name ido.ath.cx which I used to point to my home PC stopped working after DynDNS stopped being free. Instead of looking for another free provider which could also stop being free at some point, I decided to use a subdomain of my domain philippecloutier.com, which I bought from GoDaddy. Unfortunately, GoDaddy does not offer dynamic DNS, so on my friend Xavier's suggestion, I signed up for free to DNSEXIT and changed my nameservers for DNSEXIT's.
I then simply needed to setup my router to update the IP. OpenWrt allows that using ddns-scripts. DNSEXIT's website is a little amateur, but configuration was not difficult. I was surprised to notice at the end that DNSEXIT asked for a link to its website since I use free DNS. I do not wish to make an electronic payment just for dynamic DNS, but I am not entirely comfortable using such a service for nothing, so... here is your link:
The other surprise was to notice that OpenWrt's DNS update method for DNSEXIT appears to send the password unencrypted.
Meh. Not a panacea, but good enough for me.