Actual Multiple Monitors - almost same as UltraMon but with some interesting/unique features such as Windows 7 Aero Snap emulation on XP/Vista, Window Thumbnails support for XP, Start Menu on each monitor. Just check it out!
http://www.binaryfortress.com/displayfusion Display fusion. They have a free trial version or you can get a 30 day trial license to test their $25 pro version. Easier to use than Murgee and a better value for the price than Multimon.