When Blackberry went the touch way with the Storm, they added a very solid tactile response to their virtual keyboard so that the BB users don’t feel alienated towards the touchscreen. And incase you are missing something like this on the iPhone – here is VIBRUS!
Vibrus also lets you increase the intensity and duration of the vibration in settings, but the difference is nominal. The App is currently a little buggy. Would advice to wait for updates.
Vibrus works on 2G iPhones with firmware 2.x. Support for 3G is expected soon!
Cydia is an Installer alternative, that Installs on Jailbroken iPhone 2.x… Info here