Due to the usual string of code bugs and dumb thumbs, I've dinged my ArduCopter up a good bit in the testing phase. You can get a good crash repair kit from FahPah that has the most commonly-broken parts, or you can make your own. Thanks to Sandro Benigno, at least some of them (the easy-to-crack dome headers) are now very easy: just have them laser cut at Ponoko.
Just click here and add it to your personal factory. Then when you go to have it made, select the following (you'll get four pairs, which is all you'll need for life!):
Acrylic - Clear