I'm assuming that you have vertical dropouts or you wouldn't even ask this question. it is possible if you find that "magic gear" where your chain tension is ok. This means that you might not be lucky enough to have 32-16 like you wish. I had a magic gear going for a while, but now I think my chain is wearing out a bit, so I tossed a tensioner on there.

here's the relevant bit from good ole sheldonbrown:
"Adding or subtracting a link in the chain will move the axle 1/2". Changing either sprocket size by one tooth is the equivalent of moving the axle 1/8" (4 mm)."
http://sheldonbrown.com/singlespeed.html

so... if your axle is in a fixed position, you have to play around with adding/removing links or increasing/decreasing the number of teeth