There's a real one out there ... essentially, it's a few starter motors mounted to a supercharger for stand-alone operation. It runs at 36V, and is expensive.

Then there's the bilge fans that eBay sellers are marking up several folds and selling it to stupid morons. More an obstruction to the intake path, it actully is good for one thing - your mechanic. The plastic fan blades disintegrate and get sucked into your intake valves ... well, you can imagine the rest. :)

-- Kane
--

While I would never deliberately mislead anyone, take into consideration that any information and advice provided was at no cost to you.