I was actually thinking of mimicking the phone app -> add another row for send and back button and add the star and # keys.

I don't think the arrows make since -- seem a bit foreign. I think it would be more practical to allow for cursor movement by tapping. That or map the volume rocker to forward and back.

I was also thinking about adding a menu.

Thanks for mentioning the missing items.

[edit]
I literally made this right after the initial post. It's not a mock up, and I still need to find proper unicode characters for shift and perhaps realign the */+ text. On my nokia 2720, everything is actually on one row (eg "2 abc"). Would people prefer this over the two row approach currently being used?

[edit 2]
I just reread your post slender. As for padding, I'm trying to make this thing look as integrated as possible. That is, people who have n900's already use the phone app, so it should be an easy transition from it to vertsms. The phone app itself doesn't introduce padding. I could play with it a bit and see about making it a customizable option though.

Of course, this is ossi's baby and I'm just a patch monkey, so my opinions may very well be wrong and the changes that I've made to the ui might not even make it into the master branch of development :-)