I saw this article on Drudge Report this morning, about teachers in New York getting fired for improper interactions with students on Facebook. Rightfully so, too–these “teachers” are malicious perverts who deserve what they get.
I’ve seen plenty of teachers on Facebook, and interacting with students online in other ways. Their level of interaction varies from not having any student “friends” at all to frequent contact with many students. Everything I’ve seen appears to be kosher, and I hope that there aren’t any problems around here.
When I started using Facebook last year, I didn’t have a student policy in mind, but I immediately realized I needed one. What I quickly settled on was this: I wouldn’t “friend” current students or accept requests from them, but I would be open to being friends with former students. That seems reasonable to me.
Maybe the most important thing to remember is that it is a public forum–ultimately, everything online is. Conducting ourselves with such in mind will lead to fewer problems now and no regrets later.
Gently Hew Stone 
I have the same policy with my students, Jamie. It really helps to just tell it to them, and I consider it a pretty moderate position. Though sometimes you have to be quick to stear of both the “extreme problems” from each of the other sides–the faculty members whose eyebrow raise when they hear that you have any contact with teenagers on Facebook and the occasionally curious student who wonders why you aren’t friends with them but are with their older cousin or wonders why you don’t friend them like their 1st Period teacher does.