I used to own a large (and overly noisy) dell tower pc, it was clunky heavy and didn't actually perform as good as the price tag suggested. So I wasn't to sad the day it died on me. Luckily for me I ended up keeping the DVD RW drive. Looking at the label it's a NEC ND-3450A, which happens to be a 16x speed drive. For some reason every time you read about a DVD laser hack the 16 speed is mentioned. Not sure why. Anyway, after taking the thing apart I found two lasers. I hooked the bigger one up to a constant current source and voila! It works :)
Constant current source at 164mA
Laser diode running at 100mA and 2.23V.
As you can see I bread-boarded this one, the circuit was taken from this excellent thread on how to create your own laser driver.
and a closeup of the breadboard.