You know, I've been thinking about this too. I do plan to upgrade my compressor to a quieter one at some point, but I've been doing just fine with the 20-gallon Craftsman I got when I was 17.
I don't do a lot of work that requires air. Occasionally I'll do some cutting or dremel-type work with a die grinder, but that's the exception. Mostly it's for filling tires and my rattle gun, which should be upgraded soon to a battery-powered one. That being said, I am planning am autobody project over the next couple months, and air tools are a requirement there for sanding, cutting, and flanging.
My plan for my 23x23 workshop is to run a hard line (probably galvanized pipe, mostly because I like the aesthetics) up the wall from the compressor, then roughly half the wall length to the middle of the shop by the door. At the end of that I'll mount a 50' hose reel and Bob's your uncle.
All that being said, remember that I don't own a blast cabinet or any other equipment that requires a dedicated air drop near it. My BIL's shop has a blast cab, a tire machine, and a few other things that he likes to have air near. My space isn't nearly big enough and I don't have the equipment, so a hose reel and modest compressor suit my needs just fine.