http://www.wizards.com/default.asp?x=dnd/rg/20050301a
Other Options While Pinning an Opponent
Here are a few optional maneuvers for use against a foe you've pinned.
Throw Your Foe to the Ground: Make an opposed grapple check as a melee attack. If you win, your foe winds up prone in any square adjacent to the square you and your foe formerly shared. The movement provokes attacks of opportunity from enemies who threaten the space your foe leaves, but the movement doesn't count against the foe's speed for the current turn. You stay on your feet in the space you formerly shared with your foe and you and your foe are no longer grappling.
Toss Your Foe: Make an opposed grapple check as a melee attack. If you succeed, you can literally pick up your foe (provided you can lift your foe's weight). Make a Strength check; if your result is at least 10, you toss your foe 5 feet. For every 5 points your Strength check result exceeds 10, you toss your foe another 5 feet, to a maximum of 25 feet.