Can Brussels sprouts be eaten raw?
Yes, they can be eaten raw, and I do so frequently when they're in season.

I find them much more convenient for sandwich greens and salads when cooking for one than a whole large cabbage; I just chop up what I need (1-2, depending on size), and add 'em to the sandwich, or whatever I might be making.

...and I agree with Jennifer -- don't boil them.  (I like quartering them, and saute in bacon fat 'til they've browned, then a heavy dose of salt.)