??

http://graphicized.org/tutorials.php?blending_multiple_images

That's for PSP8. I don't know what image program you're using, but that could probably help even if you're not on PSP.

i have PSP7

Well, I'm pretty sure that it will work the same way in PSP7, just the tools may be in a different spot.

http://local-girl.org/malia/tutorials/blends.shtml

Maybe that might help, also.