Parallels Desktop has been on my radar screen for many months but I’ve only just had the opportunity to purchase and install it on my Macbook. This program allows you to run a virtual instance of Windows (or i386 Linux) from within Mac OS X. Though I did have my original Windows installer blue-screen (that was funny–a B.S.O.D. on a Mac),  had much better luck when I ran the Windows installation using Parallels’ "Express Setup" method.  Once Windows was installed, I put service pack 2 on and have been happily watching XP and OS X cohabitate ever since. Disk access on the Windows side is slower than I’d like, but generally the performance of the virtual instance is acceptable enough for daily use (unlike the Virtual PC of old from my G4 PowerBook days).  Really handy for working with Windows sysadmin tools. Saves me a lot of needless headaches with that crap OS X implementation of Remote Desktop Client Microsoft puts out.