As the equivalent of tattoos for your gadgets, laser engraving manages to provoke the same love it/hate it response - some view it as an awesome act of self-expression and personalisation, while others see it as a permanent marring of a tech toy and something guaranteed to kill resale values.  Still, if you're a true geek you'll love the idea of a laser so feast your eyes on Epilog Laser's video demo of one of their team's iPhones going under the demon lens.

Of course, they're not doing this for proverbials and giggles; they'd like very much for you to splash out $10k on one of their engraving machines.  Now, assuming you're not planning to engrave every single solitary item you own (plus those belonging to other people) it's likely cheaper to go somewhere that already has an engraving machine and get them to do it as a one-off, but who cares.  I just like seeing an iPhone undergo laser surgery.