Do you know about Android’s StrictMode? I didn’t a few days ago. The Android blog has a great article explaining StrictMode here. It’s about a year old now, so some of the newer Android developers (like myself) may have missed it.
StictMode is a command in Android Gingerbread that allows the compiler to catch many of the mistakes that cause ANR problems in an application and things that generally just make an application unsmooth. It catches things like file system access on the UI Thread and SQLLite objects that haven't been closed. These kind of things can really come back to haunt you in the development process if not checked.
If you’re using Android 2.3 or above, there isn’t a reason why you shouldn’t use StrictMode during Development. Even if you’re writing your application for 2.2 or lower, it may even be worth coding with API level 9 and lowering the API when you are ready to release. You should really check it out.