Possibility to invoke XMB on gamepad with no such button

i only got ps2 gamepad connected via usb adaptor. and with prices of original controllers high, im looking for alternative for that. also my current pad is better in some areas than dualshock3 :)

will it be easy to modify psgroove payload to remap controller buttons to, for example, start+select act as XMB button or hold select for 3 secs or remap L3 or R3 for that.

i know other alternatives would be:
* buy ps3 remote - high price too...
* buy 3rd party gamepad - cheap but quality unknown, only 2 usb ports on ps3...

is it possible to invoke XMB with USB or bluetoth keyboard?

im curious about modyfying psgroove source code or kernel files, if it could be done that way?

You do know that you can get a SIXAXIS for less than $20 now, right?

yeah, a new controller should not be cost prohibitive at this point.