I've had mine for 3 weeks now.
At first I wanted to get the wall charger but decided to wait and see how quickly it discharged.
The second night I left the reader plugged in to the computer with the monitor off.
Just checked - the reader is still fully charged after 3 weeks.
Every once in awhile I plug the reader in to load a book. My guess is that that is all it needs to keep the reader charged.
If you feel that you need a charger, do get the PSP charger. Best bet - Amazon for less than $4 ( but I like the looks of the one for $12.
http://www.amazon.com/s/ref=nb_ss?ur...ds=psp+charger