Re: Droid X on the way
I really like TiKL that six storm recommended. There is another PTT app called Hey Tell but it seems to drain the battery quick and it isn't instant like TiKL seems to be. It does record any missed voice messages though which is kind of cool.
I also like Scanner Radio
If your phone doesn't have Swype definately get it. Mine came with Swype and I love it.