Actually, a lot of the mystique surrounding Area 51 arose from the fact that the government continued to deny its existence for so many years--up until and past the time commercially available satellite photographs clearly showed a military base there. That and the fact that some spectactularly futuristic aircraft have been tested there (the SR-71 Blackbird, the stealth bomber, and the stealth fighter to name a few--civilian aircraft and UFO enthusiasts would see these craft long before they were made public). There's also that guy who claimed to have been a physicist working at Area 51--I think his name's Bob Lazar. He went public claiming to have worked on alien anti-gravity technology at Area 51.
USAFHokie80: on the tail number item--are you sure they were talking about official military craft not having numbers? I've seen a couple different programs on Area 51; some of the people who work at the 'secret' base there are flown in from McCarran Airport in Las Vegas; while normal commercial aircraft have tail numbers, these planes don't--they look like regular commercial airline jets, but have no identifying information painted on them (they showed video of the planes devoid of tail numbers at McCarran Airport on the program I saw).
I live in the Las Vegas Area and have been to the "Back Gate" of Area 51 a couple of times--that's the gate near Rachel, NV. I and my fellow nerd friends have had our picture taken in front of the sign that reads "Warning Restricted Area Deadly Force Authorized" and another that read "No Photography of this Area" or something to that effect. We, unfortunately, did not witness any security activity whatsoever on either trip (made me feel pretty damn insignificant

).
Route 375, the "Extraterrestrial Highway," is fun--there's lots of cattle ranches in southern Nevada so you see caution signs with steers painted on them all over the place, especially on out-of-the-way highways; the ones along Route 375 have little UFOs painted in the background. The Little A'Le'Inn is a bit of dive, but the food's edible and they have a nice selection of geek/ufo paraphenalia there. If your in Las Vegas and have a day to kill (i.e., got tired of the casinos and topless/nude shows), it's a fairly pleasant three hour drive one-way.