Doing Thin Layer Chromatography at home
Sean Michael Ragan at Makezine.com recently posted a 
great post about Thin Layer Chromatography in the kitchen - here's some excerpts:
During my six-odd years as a graduate organic chemist, probably the cheapest, most powerful, and most commonly used analytical laboratory technique in my bag of tricks was thin-layer chromatography...
[another] common reason for performing separations is analytical: You want to get an idea of how many compounds are in there and whether or not one of them is compound "X." Thin-layer chromatography lets you do this, on a bench-top, with a few cents worth of materials and a few minutes of time. It's unbelievably powerful for such an inexpensive technique.
Click here to read the complete post.