VMware Player
One of the best bits of software that ever existed, the VMWare Workstation, has been released as a free "VMWare Player":http://www.vmware.com/products/player/. It works like a charm (at least on Windows XPSP2 and on CentOS Linux [Red Hat Enterprise 4]), allows suspend but no creation of new virtual machines or changes thereto (never the less: this is still a case of _You Get Much More Than What You Pay For_).