Yea, that's a security torx. A great set of drivers for all odd bits is: http://www.wihatools.com/719collect.htm which is currently on sale for about $25 off normal price.
Sorry to dig up a 4-week old post but Tooled up have a nice little set for under a tenner for UK people: http://www.tooled-up.com/Product.asp?PID=16113&MAN=Draper-33-Piece-Security-Driver-Bit-Set
