I was reading the reviews on this toy (something I always recommend) and one parent that said she wrote "I love you's" on this when she tucked the kids in so it glowed when they turned off the light.....that got me, I'm sold.
Look at Amazon.com under Crayola Glow Station

And this....gotta love Crayola...

Then I saw this at the Toys R' Us and couldn't resist. My boys love when we go to the science Museum. They have this device in the Human Body section that you put on your skin and a magnified picture appears on the screen in front of you. Hair on your arms looks huge and the subtle wrinkles on your skin (well, on THEIR skin it's subtle anyway) looks liked a cracked mess. They love the find little open sores and and are always tempted to put the thing up their noses to see what may be inside....they're boys, what can I say.
This is an at-home version. I can't wait until they find a spider or ant to look at close up. Blah!
Look on Amazon under Eye Clops = Bionic Eye

Had to edit my post to add one more thing. It is actually a gift my hubby gave me a few years back and it's one of my faves. I think he got it at Kohls at the time....but here is a link to one just like it.
http://www.weddingaccents.com/accessories/mm-photo-bracelets-m0122.htm
and a pic....

Head over to http://www.nihoayall.com for a whole host of ideas from other mama's. They're even organized in age groups. Happy shopping!