Scissors with blades less than 4" are allowed, per TSA's website.
Last time I traveled, my scissors measured 3 1/2" and I got pulled over at every check point and my carryons were searched.
I advise bringing the smallest scissors possible, take them out of the bag and put them in the container with your shoes to be scanned, and then you should go right on through :D:D:D
http://www.tsa.gov/travelers/airtrav...ted-items.shtm
PS I always check this site the day before I travel, to make sure there haven't been any changes :wink: