Recent reports suggest that Apple executives are in talks with Immersion, the maker of haptic software, to license the latter's technology for use in the iPhone.

Haptic technology gives people sensory feedback--like vibration or pressure resistance --when using a touchscreen. It makes pressing a key on a touchscreen seem more like pressing a physical button. The iPhone touchscreen does not provide that sensory feedback. This makes using the touchscreen more challenging for people in general, and extremely challenging for those with visual or motor function impairment, because there is no sensory indication that a key has been touched and the phone has registered it.

For more details, see the two short news stories below:

http://www.palluxo.com/2008/04/25/leaked-apple-to-licence-haptic-technology-for-iphone/

http://www.news.com/8301-10784_3-9929793-7.html