Yep. Do it. Everyone loves posting pictures of themselves taken at myspace angles, with dim lighting, with your best flirty smirk and bedroom eyes. Well, I want to see some unflattering pictures. Pictures taken while you're mid-bite/chew/word/blink with your eyes closed, while you're making a ridiculous face, possibly taken from a really awkward angle. They're the best.
Keep it kid-friendly. No unflattering nudes, thanks.
One of mine:
28th birthday (St. Pat's), wasted at an Irish bar, my friend who took the picture said I was watching something. We're still not sure what.