At-home tests for everything from salmonella to HIV

At-home test kits used to be limited to blood sugars and pregnancies, but nowadays we have so many more options. There are now home tests that can tell you your cholesterol levels, tests for detecting symptoms of colon cancer, telling you your HIV status, and even for allergies. There are even tests becoming available for things like making sure your coffee really is decaffeinated (a simple dipstick into your cup), seeing if the glass of wine you had last night made its way into your breast milk (and if it did, when it's gone), and a way for testing food for salmonella and E. coli.

Some of these sound like really good ideas, but some of them are also a little expensive and possibly dangerous. For example, if you suspect you may have colon cancer do you really want to rely on a home-kit for completely accurate results?