E.g.
i will never use the word "youth". Instead i want to use the word (made up and inserted into user dictionary by me) "youtg".
On a QWERTY keyboard, the 'g' and 'h' are close, so when i miss tap a bit, the word 'youth' will be selected (ofcourse, who wants to use 'youtg' ?

I've seen this feature in other keyboards (swiftkey x for example) so i know its handy and possible.
Also, as another feature request, something i've seen in the 'gingerbread keyboard app': a function that when you slide the 'spacebar' up, the navigational arrows would appear. This is handy for users without hardkeys (like me, HTC Desire HD) and quicker then going to 123 and then <> modus

btw, still best keyboard app on the market guys!