2 tips: make the send button half as big and make another button that acts as a arrow right. wich will be used to fast forward when you wanna type 2 of the same characters fast after eachother (now you have to wait a sec)

and second, it would be awsome if the vertsms was executed when in conversations > new sms the n900 is flipped vertically.

And offcourse T9 would be very awsome