I did the mod(sans diode and just the one wire), and it does charge the deive, but when i also have a card inserted, i get a constant usb connected/not connected (constantly switching back and forth). if i remove the mmc, it just charges with no error.
Any ideas?

EDIT: Well, i took out the MMC and reinserted, and now it seems to be working fine. I guess it was not fully inserted when i put it back in after install... very weird. But it now works 100%. can read it from the device or from windows while charging. Thanks again!

EDIT2: I let the device charge all day from almost dead (well, 6+ hours) and it was still charging. It does show full, but i guess the amperage from the USB port is not enough to fully charge LION. I will continue to experiment, but definately a worth while mod.