[dexterq20]

If you click on some people's personal profiles, there's a link that says "download vCard". Last time I checked, it was a bit harder to get a vCard than just "right click, save as".

 

[SkaredShtles]

It's a "business card" in a standard format. Lets people publish their contact & personal info in such a way that most PDAs, phones, email apps, etc. can read it.