My original assumption was that it was a widespread practice, but now I think it's much more rare than I had assumed. Which is strange, considering the savings to the business on office infrastructure, etc. and the availability of communication tools like IM, Skype, VPNs etc. Not to mention cheap airfare when you have to make that site visit.
I am also interested in promoting the practice-- if you are a telecommuting wannabe, you should say so as well.
I want to live in paradise and no one else seems to want to (although, if you all did, it wouldn't be paradise any more)
-Kent Beck (on the extremeprogramming mail list)