Just an aside...
In terms of investment / returns:
1. You look at the screen all the time,
2. You experience the processor all the time,
3. You end up managing your battery life whenever away from AC.
TC1100 Pentium M
1. wider viewing angle (this means you will spend less time adjusting/tipping the Tablet PC to see it)
2. although you won't notice the difference for light duty office tasks, for processor intensive tasks, you will have more "headroom" and better performance
3. You should get better battery life with the Pentium M
At least in Canada, the warranty is 1 year for the Celeron and 3 years for the Pentium M.
I would go for the Pentium M model and defer the headphones until later, because you *can* get the headphones later. You can't get the improvements noted above if you forego them now.