I think vmware is a nice choice, I've got vmware fusion beta 4 running on my macbook (running many Oses: netware 6.5, solaris 9, solaris 10,Red hat linux enterprise 5 server,Suse linux enterprise 10 server,debian linux 4.0,OpenBSD 4.1 server, windows 2003 and back track linux).
The best thing is I can use backtrack linux using usb wireless card to do some penetration testing using aircrack,etc...