Parallels Desktop is proving to be a popular item at the New York SOHO Apple Store. It sold out the same day the software hit the shelves.
Parallels Desktop lets you run additional operating systems, like Windows XP, on Intel-based Macs while Mac OS X is running. Appleis free Boot Camp software lets you boot your Mac with either Mac OS X or Windows XP.
While Boot Camp can potentially offer better overall performance, Parallels Desktop has the advantage of letting you use Windows and Mac OS X at the same time.
[This article has been updated with additional information from Infinite Loop.]