[photon_off]

I personally enjoy collecting scientific gadgets that fascinate me like a child. I have an IR thermometer, pocket microscope (might get a USB one soon), range-finder, digital caliper (measuring the height of a piece of paper is surprisingly gratifying), altimiter, multimiter, scale (not as precise as I'd like [10mg]), and weather indicator.

Eventually, I want a collection capable of measuring any attribute of anything I come across. On my list: lightmeter, wetness-ometer, electron microscope (when I hit it big), soundmeter, and smelloscope.

[Kliment]

Try this, homemade electron microscope (appears to be WIP):

http://www.chemhacker.com/topics/stm/

Or this, a finished, working one:

http://sxm4.uni-muenster.de/introduction-en.html

[mechanical_fish]

These are STMs, by the way, not electron microscopes.

Making an electron microscope is probably a more expensive task for the homebrewer, because you invariably need a vacuum-proof chamber with a door that can be opened and closed, and the pumps to evacuate it...