I think its a waste of time, why? Because half the time you waste your time looking at other people's profiles and their photos and then commenting on their photos or wall with your one liner haha hehe, and the other half the time you waste your time looking at photos you've been tagged in and check out what people wrote on your photo or wall. Its voyeuristic, superficial, and its only for those who want to feel a sense of belonging in the world, people have hundreds of "friends" but more than half of them they don't even see or talk to and some you may not even know haha.. its sad if you feel good about having hundreds of friends but yet only a few in the REAL WORLD.
At the end of the day if you're SERIOUS about your sikhi then you don't need to feel a sense of belonging in the world, you only need to feel a sense of belonging in the presence of saadh sangat and guru sahib, once you feel like the only thing you need to belong to is maharaj, you're doing good.
You're not gonna become a gurmukh by checking facebook 2-3 times a day, which is what it turns into after a while. And instead of getting addicted to naam you get addicted to a site which becomes your life. I'm not hating but its just some things I noticed while my time lasted on that site. On top of that is the stupid teenage giggling when talking about some silly games or pranks or jokes or gossip on someone's picture or an inside joke. Bottom line, its a "social networking site" and if you're serious about your sikhi you shouldn't waste your time on it, rather read a book, learn a instrument or start a sehaj paath. As far as events go, Im SURE you will hear about an event or find out from one of your mates.