It would be nice to have a ledger for tracking mileage, and ability to import info from pda's (later concern). It would take relabeling current ledger categories, adding 1 or 2 more entry field, and creating a "stock symbol" for mileage.

Ledger entries would include:
1) Date
2) Mileage Category (user define-able accounts: business, medical, moving, auto-typing fill, with "mileage" stock-symbol as account currency)
3) Start mileage (in stead of "check/invoice number") automatic fill from previous end mileage record)
4) End Mileage (added field)
5) Where: (instead of description)
6) Purpose: (instead of memo)
7) mileage rate (exchange rate) (user defined, but automatically uses last rate defined until new rate is entered, so don't need to edit it with every entry)
8) maybe show mileage for each individual trip (start minus end mileage) in ledger, but most definitely in reports.

The actual rate (50 cents per mile) is subject to change on occasion, so tracking bare miles instead of guessing a cost would be preferable, too.

Yes, U.S. mileage tracking, though I don't know if other countries use this sort of thing, too. I just happened to be reading the IRS publication relating to this before I posted it, and here's the link to it if it would help. But basically, if one chooses to track business-eligible miles instead of actual travel expenses, they can take a deduction of 50 cents per mile for 2010... http://www.irs.gov/publications/p463/ch04.html

I guess by "mileage" you mean a U.S.-specific tax thing where you must record the car's mileage and the respective occasions for which you have used the car? For people outside the U.S. (e.g. me - I'm German) the requirements for this feature are not at all clear, so maybe you must explain this further.