I happened upon ubreakifix by chance via a link in my Gmail. (I often just thought those were useless.) After just managing to slip in there before they closed I heard back the very next day about what they could do to repair my iPhone. I had already decided to buy the newest iPhone so I just sold them my broken 3GS - they pay $60 if the screen isn't working but I hear that if it is they'll pay $120 for it! iPhone has a high resell value and this is the place to sell if you want some good quick cash.
I also recommended them to a coworker upon noticing his iPod touch screen was broken. He took my advice and got it replaced for around $60 and was very satisfied with the job. The prices may sound high but that could just be the deal for Apple products. When I went they didn't have any kind of sign up outside so it was hard to find - I was worried the internet had tricked me! It's just to the right of Staples looking straight on at it. The service at ubreakifix is incredible - every person I've seen working there is polite and very helpful. Highly recommended!