i have a little 3 gallon, its pretty much worthless, even for blowing your computer out too... compressor kicks in like 5 seconds after you start sprayin air, and takes forever to fill. So my point is, DO NOT SKIMP, you'll regret it later, I know I do.
+1
Pancake compressors are very noisy, they're usually oilless so that won't last long either. On the plus side, they are portable.
I picked up a vertical tank compressor for cheap off CL and couldn't be happier
Similar to this
They don't take up much space in the garage, they're big enough to do most kinds of nailing/grinding, I've even run a framing nailer with it. It won't be enough to sandblast, but I haven't had the need yet
And they have wheels, so you can move em around relatively easily.
Everyone I talked to about compressors said if you don't want to be buying a new one every year or so, get an oiled compressor. Yeah, they're a tad more work, but they'll last forever.