DioPen is a handwriting recognition keyboard replacement (like Swype) for Android that I find works quite well. Works very well on the resistive touch screen of my PocketEdge, and works almost as on the Acer A500's capative touch screen (using an approriate stylus, finger is useless IMO) - you just have to write larger. Being an Old School Palm user, I also have Grafitti as an input method as well.
Which one I use will vary, depending on conditions. If I'm sitting down, and can hold the tablet relatively stationary, I'll use Diopen. On the move, or standing, my handwriting degrades so I'll use Graffiti which forces you to make the characters in a predefined way. If I'm at a desk, USB keyboard.
I also use WritePad for iOS on my Ipod as well - also recommended.
What I'd really like to see is more tablet makers offer watcom Penabled input along with the capacitve touch. It can't add too much more to the cost. They could have a hardware switch to switch between the two (or auto-sense when the pen is near).