To use on a 'home' broadband system you could get a static IP address, which would be expensive or impossible. However take a look at www.dyndns.org - you get a domain name and setup the DNS with dyndns.org, run a bit of software on your machine, and this updates every time your ISP changes the IP. It works BUT, a broadband connection is asymmetric, which means that it is really dreadful as a server connection. The speed will be very slow in that direction. However, as a test site it is perfectly feasible. For example, I use this so I can connect to my home machine when I am away to get files and such - if the IP changes I don't have to worry about it.
Ideally, though, install on your server.