I have to pimp my sheet a bit.
My
SSA-X2 D&D Character Sheet is PDF form based, and thus you can enter you character data into the sheet within Acrobat, and the sheet will do the calculations for you. The sheet has many features for managing lists of equipment, spells, weapons, etc., and you can change the sheet layout from a basic 4 pages to a colossal 27, depending on your needs. I'va also been able to create a sheet edition which will allow you to save you data even if you're using Acobat Reader (a feature no other PDF sheet I've come across has yet).
You can check it out at:
SSA-X2.com
If you have a slower computer, I recommend turning calculations OFF while entering character data. I'm in the process of rectifying the slowdown for the next revision.
<end shameless plug>