Quote Originally Posted by Chayat View Post
I don't mean one of those 40w CO2 lasers...

Just something out of a DVD burner should be able to mark plastic pretty well. there are instructables about building CNC engravers with them: http://www.instructables.com/id/Pocket-laser-engraver/

What you speak of would still be very easy to do. The new laser isn't soldered onto the board instead there is a 3 pin socket that you can push any standard laser diode into.
I Think nearly all DVD lasers will just work. We are alwase thinking about how to make the Peachy Printer convenient to modify. If you do a modification like this be sure to read up on Laser safety ! and include that in your posts about these modifications.