LISTBABY: your email list mailer
Instead of sticking everyone you know into "BCC:" field of your email program, an email list manager on your site will let you email some or all of your contacts, using their name right in the email itself.
You can send announcements that say "Dear Bethany..." and "Dear Evan..." instead of "Dear Fans and Friends...".
The emails are sent directly from your webserver, so you don't have to worry about Earthlink or AOL limiting how many emails you can send!
You keep your contacts safely on your own website, so you can access them from anywhere on the road.
There's a full tutorial on it, here.