I have two!
Offline BFF I've known since we were 14. Freshman year of high school. We weren't BFF's back then, but in a close circle of friends. We got closer as the years passed. So we've been friends for...almost 20 years! Crap!
Online BFF I've known since 2004 so... about 7 years? Not too bad!
Here's to many more years!