I recommend Thomas M. Disch's marvelous book The Dreams our Stuff is Made Of. It's a thorough study of how science fiction has influenced scientific and social developments in the 20th century.

This technology wouldn't work for me.

99% of my calls are from girlfriends who only want me to listen to them go on for hours about their problems. I never get a chance to say anything.

No 'Little Lulu'?!?

I really like the pocket-sized Russian Geiger counter I bought off the eBays a couple of years back for under $50. It gives off a reassuring click anytime you come near anything remotely radioactive. It even clicks when hit by stray cosmic rays. Here's a current auction for one like mine:

http://cgi.ebay.com/NEW-RADIATION-DOSIMETER-DRSB-01-Geiger-Counter_W0QQitemZ310098505503

Of course, you'll also need something radioactive to detect. I suggest a bit of uranium from United Nuclear:

http://www.unitednuclear.com/

If Hollywood films about 'hackers' have taught us anything, it's that a teenage hacker with a laptop can insert a handwired card into any slot and generate random characters until the proper password is found. I suggest a similar automated approach to this problem.