My primary occupation is that of a naval architect at a marine consulting firm in Seattle where I regularly perform calculations on engineering pads and in Excel while trying to solve problems. I am trying to use my Samsung Q1 UMPC as much as possible to replace paper and just read about the latest release of xThink's MathJournal 2.0 application on the GottaBeMobile website. BTW, they are giving away a copy of MathJournal to one lucky winner (full retail price of the software is US$249).
MathJournal 2.0 looks absolutely amazing to me as it allows you to handwrite complex mathematical problems on your Tablet PC and have the software recognize the expressions and compute the answers. Some of the new features in MathJournal 2.0 include new advanced functions with their function library expanded by 75%, Greek symbols (used all the time in my calculations), matrix operations, support for keyboard control, and more. I also like the fact that you can save pages as images and also paste images into MathJournal. My office is moving to everything electronic and it would be great to also have my engineering pad calculations in electronic format without having to scan in paper copies.
I will have to go download a trial copy of the software and give it a try on my Q1 to see how well it performs on a non-standard resolution of 800x480. I also see on the xThink site that they have quite a powerful Calculator available for US$44.95 that may allow me to dump the HP48G model I use daily.