What to buy a geek for the holidaysMatrox TripleHead2Go: This three-headed monster is the ideal computer monitor for the busy geek in your life. "This made me go, 'mmm, three screens at once,'" wrote Prudential Fox & Roach Realtors senior systems engineer and avowed geek Tory Skyers in an email. "I could have a kernel compiling on one, my Web pages and such on the other, and my email on one too, while I work on something on the fourth, if I use a laptop … gimme a minute to come up with something else I could work on..."