These are just freaking cool... but I'm having a hard time figuring out what I'd actually use them for.  I guess it's just another one of those things that only a geek would understand.  But just the fact that something so small can have so much holding power is freaking cool.  You can find out more about rare earth magnets here.  In fact, one could argue that rare earth magnets have contributed to the computer industry just as much as transisters have.  There is a page with all sorts of interesting ideas... and you just have to love a product that comes with a warning like this:

These magnets are very strong and should be handled with care. Small children should not handle these magnets. Older children should be supervised at all times when handling these magnets. These magnets should not be ingested. If the magnets are allowed to snap together or against steel, they will chip and crack. You should keep them at least six to twelve inches away from computer hard drives, credit cards, computer monitors, and other susceptible electronic equipment. Individuals with pacemakers and other internal medical devices should not handle or come within close proximity of strong magnets. These magnets are safe for air transport as packaged but as a general rule they should be kept off airplanes.

And seeing as how my life is surrounded by computers and electronic equipment... I'm not sure I want to worry about accidently bringing my cool new toys within range of something I haven't backed up in a while.  But still....