I tried to think of a good engraving for a couple of days before buying it, but I couldn't think of anything that would last more than a couple of months without me regretting it. Besides, I figured it would lower the resale value, so mine is just blank.
Not a thing. I prefer to keep it nice and clean and engraving-free. I've found a lot of people put quotes that become dated, phrases that are trendy, etc. I doubt I'll ever find reason to put any sort of engraving on my Pod.