you can go to 1and1.com registere a domain and you get full dns management and web forwarding.
combine that with an account with dyndns.org
install the dyndns.org client on you server/router
and off you go.
example
at 1and1.com you register linuxadict.com
at dyndns.org you get linuxadict.dyndns.org
and you set the webforwarding for
www.linuxadict.com to point to linuxadict.dyndns.org :-)
or, you leave out the 1and1.com registration and leave it at linuxadict.dyndns.org
sorted :-)