LucyPhone is a great free app, available in Android market (not sure if they have it for iPhone).
Basically when you call a company and don't want to wait on hold, it enables you to hang up and calls you back once the rep comes on the line.
Plus it has a directory with more than 1600 companies phone numbers, including hard to find ones, such as Amazon and PayPal. This directory can also be updated periodically for more numbers.
No brainer!
