fprintf writes "As much as I hate to admit it, it looks like my 13-year-old son is following in my footsteps and preferring interesting, science-based toys. In the past he has been really interested in Lava Lamps, Newton's Cradle, and anything magnetic. It seems the knick-knacks that have generated the most interest were small and relatively inexpensive. For example, a small laser pointer keychain I bought him a couple of years ago still provides tons of entertainment. Yesterday I showed him ThinkGeek and he really liked the Levitron. I wanted to ask the Slashdot crowd what were some other really neat, interesting gadgets? Is there anything cool in the under-$50 range that you would like in your stocking this year?"