Air compressor alternative?

[BrianG]

I have a small 1-gallon (maybe 2, not really sure) portable air compressor that I use to blow the dust out of my various computers, but I would like something better.

The compressor I have is small enough to be portable, but that small size means that the tank doesn't hold enough high pressure for long enough to do the job. So, I'm always waiting for the pressure to get back up to ~100psi. And I'm not the most patient person. A bigger tank would be the next logical step, but that would reduce portability and take even longer to build up the pressure I want. A larger overall compressor is even less portable.

"Canned air" is expensive at ~$5 a can. It takes just about a full can to completely blow out 1 computer, and I have 3 computers, so it can get rather pricey just to clean them.

I know regular "biscuit" fans won't work. I can get high-flow fans, but they don't have high pressure when you restrict the flow at all, like you'd get when you attach a funnel and ~1/4" nozzle setup (which is what I'd be doing to make something to clean my PCs). Any back-pressure and the air "leaks" around the fan blade tips. To get around that, I thought maybe an R/C EDF setup may work, but I read that if you restrict the exit port too much, it tends to stall the blades.

Are there any other alternatives/ideas?