On our Bamboo tablet the feeling is a lot better than on a iPad for example. But we're optimistic about iPad and Android tablets getting closer to the paper feeling.
http://adonit.net/product/jot-touch/
Looks pretty darn close to feeling like paper. Pressure sensitivity doesn't matter for your app, but their other stylus options are fast and accurate too.
Any chance your app will work on my touchpad?
[EDIT] They also have JotStudio coming out. The app works with the pen and "overwrites the default finger offset, giving you 100% accuracy with the world's most accurate stylus."
They have an SDK so you can also support their pen. Sigh, I guess I need to buy an iPad3.
Do you mean an HP Touch Pad? We don't have one, so we cannot say anything about that currently. It depends on its JavaScript and Canvas performance in the browser.