I was wary of Facebook initially, but a half-dozen librarians at EIU decided to sign up last fall, as one of us had been reading about the possibilities for promoting library services and events there... "Go where your patrons are" is a guiding principle in libraries these days. I've poked around in the system, joining a few historical fiction-related groups (which don't seem to get much traffic), friending people I knew, and, of course, checking our library apps to make sure they continue to work. I regularly update what books I'm currently reading, change my status line to something pithy, and see what all everyone else is doing - nothing too complicated.
I'm still not sure how people spend hours and hours there, but I'm pretty impressed with it as a social networking tool. It lets you learn more about people you interact with mostly online, and I've used it to stay in touch with friends I haven't seen in person since high school and college.
My Facebook profile is here, and if you're a regular reader of this blog, feel free to friend me. There's a group just for Sarah Johnsons, which freaks me out, considering it has over 300 members. Some of them even have my middle name.