I heard that theres a 50/50 chance of breaking the PSP if you mod it to play games on the memory stick. Is this true? Replies appreciated

There is a risk of "bricking" a psp by installing new firmwires and such, but it's not 50/50. More like 5% of the time - custom firmwire seems pretty safe now.

Are you talking about downgrading your firmware here? Yes, there's a chance of bricking, and it should be lower than roguetide stated, more like 1 out of 40 will brick if you follow guides exactly, and ask if you don't know. If you want to downgrade to be able to play games off memory stick, then you'll need to have 3.50 or lower (as in 3.51/3.52 can't downgrade), the lower the better.

Yeah cos basically, my friend wanted his one downgraded like mine,but I have no idea how to do so. But basically he wants his psp to think its a 1.50 but really its a 3.50 or something like that. So that he can play games on his memory stick. replies appreciated

What's his firmware version? 3.5? If you follow the readme's and are patient and careful you won't brick your PSP (very tiny chance). But I'm going to go with saying that your friend is going to have to downgrade cause you can't 'fool' the PSP like that. Just grab Lumines and downgrade.

Duh. If you don't want to downgrade, there's not much you can do... My advice, downgrade get 3.52 m33, then post your results here.