Since last I posted, I moved WAY south (lil warm down here) and the house I moved into was a foreclosure so a few things needed done, namely the AC and furnace. When the guy did the job he said he would (did?) leave the old motor behind so I could use it for some airflow in the garage. Here's what it looks like...

Onto my real questions -- I don't have the wiring diagram, but if I had to guess, I'd say that plug is a speed control (black the common?), and the white is the hookup. Is that right? And has anyone rigged one of these up and if so, how'd you do it?
==== updated 7/1/2012 ====
I got motivated today and started to clean it and look for tags that might help identify what it is -- and well, I think this answers everything (and I got a good picture of it!). It's a Westinghouse 323P683 1/4 hp, 115v motor so xcythe you we're close on those wires (much better than my guess).

If I'm reading this correctly...
White-Red : low speed
White-Blue : medium
White-Black : high