Next time you're stumped for a gift, try the Met Gift shop. I guess you can't call the posters, art books, mugs, jewelry, serving dishes and toys "originial" since most of them are based on art on display in the museum, but a lot of the pieces for sale certainly are unique.
I'm a big fan of the educational children's books and toys - gladiator action figures and monet coloring books beat Teletubies hands down.
Admittedly, some of the stuff in the shop is a little tacky, but that's also part of the charm. Someone in your life is bound to get a kick out of a Van Gogh inspired umbrella.
If you get the timing right there are some really great deals to be had - I just caught a 50% off sale on a whole bunch of reproduction vases, tea-pots, etc.