There are 3 ways to run TRIMS on a Mac computer. In each situation shown below, the user is required to purchase the Microsoft Windows® operating system if it is not already installed on your Mac.

Boot Camp with Mac OS Leopard - When you're ready for Windows, the Boot Camp Assistant sets up your hard drive for you. It leaves all your Mac data in place while it creates a separate partition on your drive for Windows, and then begins the installation process. 
After you’ve installed Windows using Boot Camp, you can start up your Mac using either operating system. Simply hold down the Option Key when you power up and choose one or the other. www.apple.com/macosx/features/bootcamp.html 

Parallels Desktop - Run Windows, Linux, and more side-by-side with Mac OS X on any Intel-powered Mac, without rebooting. With Parallels’ award-winning virtualization technology, you can run Mac OS X and Windows at the same time. You can even drag-and-drop files between desktops.  www.parallels.com/files/upload/Parallels_Desktop_for_Mac_Datasheet.pdf 

Vmware Fusion - Installing Windows has never been easier, thanks to the Windows Easy Install feature in VMware Fusion. Just answer a few simple questions and insert your Windows installation disc—VMware Fusion will automatically create a Windows virtual machine that is optimized for your Mac. You can also use the New Virtual Machine Assistant to create virtual machines that can run Windows, Linux, BSD or any of the more than 60 different operating systems supported by VMware Fusion.  Are you already running Windows XP or Windows Vista on your Mac using Apple's Boot Camp? No problem. VMware Fusion automatically detects your Boot Camp partition and lets you access it as a virtual machine, giving you the flexibility to run Windows XP or Windows Vista alone or side-by-side with Mac OS X, www.vmware.com/products/fusion