GPS location tracking is one of the features we have in mind! Great to hear someone else is keen for it.
Something else that we haven't seen is better browser integration - some kind of bookmarklet that gives you a timer whatever site you're on in your browser. This would be good for web developers and other users that spend a lot of time working in the browser. What do you think of that idea?
What would be a cool feature, is if you could use the gps as the timetracker. You were at the location 10 hours, how many do you want to bill etc.
Just an idea :) Simplicity is nice, but lots of your competitors have that already. What sets you aside?