Play Zynga Poker for a free Mafia Wars sleeve gun
"Ace in the Sleeve" is the newest Zynga cross-promotional item since the YoVille Snail in FishVille (plus many more), but this time, it's being done between Mafia Wars and Zynga Poker.
The gun being offered has a very impressive attack stat of 53 pts. Its defense is a below average 23 pts. In order to get your gun, click on the Zynga Poker advertisement within Mafia Wars and play until Level 6. This should take you just a round or two. The free gun should show up in your Mafia Wars inventory page.