Yes, one plant per sq ft works great. If you have the room 18" squares would be better as one per sq ft doesnt give any room to tend to crops. If you are doing a small plot where you can reach into the center from the outside i do one sq ft otherwise do 18"

FWIW, I plant mine in rows 12-14" Apart X 6 rows deep. That provides ample pollination and it can be harvested from either side. Weeds aren't a great concern as you can get in and weed until the corn gets tall enough to shade them out.

The space you have is going to provide a lot of corn if it's all planted and the same harvest date. I'd do two or three plantings to extend the season and offset any issues with late frosts, etc.

<Does that mean I can plant 288 plants (12' ×24')? Thanks in advance.>

Not really as you would need some access paths in there somewhere to care for the plants, have room to do the side-dressing, check for pests, harvest, etc. Plus you really wouldn't want to plant them all at the same time, right? You'd end up with all those ears at the same time. Stagger plant the area at 10 day to 2 week intervals.

Link to many of the previous discussions on corn spacing for more details:

http://www.gardenweb.com/gardenweb/query/corn-spacing

Dave

Thanks everyone.