NeTraverse's Win4Lin allows you to run a Windows 9xsession under Linux, so you can use Microsoft Office, Internet Explorer (as much as I like Konqueror, IE is still zippier), and hordes of other Windows applications. As of version 3.0, Win4Lin supports parallel and serial port access in Windows, as well as all sorts of ways to configure the way drives and partitions show up. However, it does not support DirectX, so no games...

If you ask nicely, the NeTraverse sales staff will give you a evaluation key to run Win4Lin in demo mode.