These great ideas were originally posted at one of my favorite new blogs, Rule the Web (named after the book by the same name by Mark Frauenfelder of one my other faves, Boing Boing)
Idea 1: Free voicemail from AOL, called AIM Phoneline. It's a free service if you settle for incoming calls. If you don't want to give out your main phone #, it's great. My number is 864-335-6221. Here's the link. You'll need an AOL or AIM (?) account to get the number and check your messages online, but it's free.
Idea 2: Using Twitter. I have a twitter i.d. (steplow) but it's pretty useless without a network of folks to interact with. Mark has a list of ideas for Twitter's actual real-life usefulness here. Let me know if you sign up.
Cheers!