What with FAO Schwartz going out of business, I decided to take a wander by... and what do I see but a Digital Blue QX3 Microscope for sale.
OK, big deal, you might think. But when the Proscope costs around $200 for just a base model, this thing at $30 bucks is a steal.
Mac OS X isn't naturally supported, but there's freeware in the form of miXscope, which works just dandy.
Here's a quarter at 200 times:
And 10 times, just for reference.