I've just installed a handy bit of freeware called Touch Response. The idea is very simple- it vibrates the phone when you touch the screen. This is actually a lot more useful than it sounds. The problem with touchscreens is that they don't offer any real feedback so sometimes if something is a little slow to respond, you wonder if you actually pressed the screen or not!
Touch Response solves this by making the phone give a little 'buzz' when you touch items on the screen. It also isntalls a little applet to the System Settings so you can fine tune the action - it can vibrate for an adjustable time on press/release. Yo ucan also select when it should / shouldn't work, for instance disabling it when the stylus is out, or during a call.
You can download Touch Response FREE from here: Touch Response