Recently a bill has been passed that makes the path to citizenship for the immigrants much easier.
It states that any immigrant living in the USA legally (on status) for two years can join US army and get citizenship in as little as six months. But you'll need to serve in the army for at least four years. This is, I guess, a great news for us. I understand, there will be many opportunities after joining army (like chance to furhter study, works in the same field of study, etc).
I guess, specially this is good news for those friends who marry American girls for the green cards.
Take the chance!