CodeWeavers has released CrossOver 7.0 for Mac, adding support for Microsoft Office 2007, Adobe CS and CS2, and improving "online banking integration" in Quicken 2007 & 2008. Unlike Boot Camp or virtualization solutions like Parallels and VMware, CrossOver allows you to run Windows software on your Intel Mac without actually running Windows. Other changes include various bug fixes and improved support for IE and "modern Linux" distros like Ubuntu.
CrossOver 7.0 is $39.95 for the Standard edition and $69.95 for the Pro edition that includes CrossOver Games and more support. A demo is available for download.