I use one of those dreaded 2200mah batteries bought off Ebay (~$15 if memory serves me)
Pro's-
It didn't fry my Axim
It lasts at least twice as long as the OEM
It's door fits better than OEM. No "battery latch was unlocked" warnings (guess you get what you pay for!

)
Con's-
Battery sticks out the back like a pregnant guppy
Increased weight
The Axim is unbalanced when sitting on its back.
I would be much happier with a design that increased the thickness of the device evenly! This is the last Axim I'm buying

!
__________________
012009
Sharp Zaurus 5000 > Sharp Zaurus 5800 > Casio E-100 > Casio E-115 > Dell Axim X-5 (forever lost

) > Toshiba e805(Wifes "new" PDA) > Dell Axim X51v >+ Verizon xv6700