Any tips for phone stability?

My Moto Droid has seen great performance improvements with each new Android version, and has been much more stable and reliable with each version release.

Recently I was in a situation where the phone just didn't think it had a cell signal, and then wouldn't disconnect the call that it couldn't place because of the non-existent cell signal. Ultimately I had to reboot the phone to get it to be usable again. This happened when I really needed to make a call and was a huge hassle. Having a smart phone with tons of data network features is great, but I still pay more for minutes than I do for data (thank you US carriers...) so not having it function as a phone when I need it is very frustrating.

I'm running Android 2.2 and don't use many widgets nor do I keep many programs running that use background services (don't usually keep GTalk connected, etc)

Does anyone have any general tips or apps to avoid to help keep my phone stable and reliable?