Tinnitus is very common. I've heard it affects something like 15 million Americans !
As far as I know, there is no cure.
I definitely have tinnitus. I think it's just in my left ear. It feels plugged up, and has felt that way for a couple of years. I've tried those ear drops on like five occasions but they never work. It was like that in both ears, but as luck would have it, my right one came unplugged completely randomly the other day.
I definitely have a ringing in my ears, though. It sounds like it's coming from inside my head. It's not a huge deal, but I have trouble hearing and stuff, so I have to ask people to repeat things often. Never prevents me from going to sleep, and I'm not really bothered by it. I'd say it only makes it harder to hear... that's about it.