You can host your own site, mail server, etc. even with a dynamic IP.
There are some programs (like DYNSITE - google for it) that updates either dynamic DNS websites (like cjb.net) or DNS servers that can handle DYNAMIC UPDATES (like the one I am using).
Every time your IP changes, it updates the DNS server and your site is updated.
I have helped a friend to run a co.za domain from his home on ADSL. (www.itsystems.co.za)
How can you host a website when there is so much latency and only 8.5kb throughput on the 128kb they sell you?
512/128 (5) will cot you R30 000.00 per month and give your web visitors 102.5kb download speeds.