I just whipped this together to help someone in another post, and it turned out good enough to show off here I think. I provided a link to the source (its too big)
SWF: http://jsites.no-ip.com/Flash/exp/paintcan/paintcan.swf
FLA: http://jsites.no-ip.com/Flash/exp/paintcan/paintcan.fla
ZIP: http://jsites.no-ip.com/Flash/exp/paintcan/paintcan.zip
UPDATE: I added the size variable (to control to size of the pixels) plus I made it round the position so that there is never half overlapping
