I've been looking around for a laser etching as well. I went asking around my local mall and discovered that some Jewelers are willing to etch my computer They require an image with at least 600 dpi, GrayScale preferred.

It was estimated at $150-200 so whenever I get an image I deem worthy, I'll go there and see what's up.

You may want to try looking for a local jeweler willing to do it since they deal with inscriptions on a normal basis