You didn't say if you have a static ip or not, if you do you can sign up for dns from dns2go.com, they don't have a client side for linux I don't think but you can log in at there website and set the static ip you want a domain to point to, there service is FREE too, I am running 2 sites with it right now,
http://www.marcusandmeagan.com and
http://lakewoodlighthouse.org these site are sitting on a server in my girlfriends basebent running off a dsl line. I hope that helps you some.