This past weekend I took my iPhone 4 running iOS 5 beta to the Apple Store because I had been having problems with the home button for a few months prior.
Basically the home button wouldn't respond as well as it used to. I'd have to click it harder because light clicks wouldn't register, or sometimes I'd double-click and it would register as only one click or as a triple click (which I have set to invert colors). So I knew it had worn out prematurely.
I set up a genius bar appointment and told them the issue. The Genius checked inside the dock connector with some sort of tool and for water damage, but didn't find any. Then he told me that he would be able to replace it except he couldn't because I was running iOS 5 beta which wasn't supported by them. They said that it was their beta, but they still didn't support it and that restoring the phone would just leave it back at iOS 5 beta, so the only way would be if I had saved a file on my computer that I would need.
I knew he was talking about the blobs, so he said if I could get it back to iOS 4.3.3 and bring it back they would swap it out. So I did that, which was more difficult than I expected since I kept getting error messages when attempting to restore, but I finally did it and took it back. A different genius looked at it and told me that they don't have parts to replace the home button, so they would just have to swap out the phone. I was glad as I had some light scratches on my screen, back, and bezel. The battery was also a year old since I only had 10 days left of my warranty, so I was glad to get a refurbished phone that was basically brand-new. So now I have a new phone that works perfectly!