With all the power that today's computers have, why be content to run only one operating system on them? Thanks to modern advances in virtualization technology, you can run multiple operating systems on a single computer at near-native speeds. There are many choices for virtualization on Linux. On the proprietary end, you've got applications such as VMware, and on the open source end, you've got Xen, coLinux, and QEMU (for more information not covered in this chapter, see http://fabrice.bellard.free.fr/qemu/).
If you don't need a full-blown virtualization environment, the open source Wine suite may be just what you need: it's a call-level reimplementation of the Windows Application Programming Interfaces (APIs) that allows many Windows programs to run unmodified on Linux. With proprietary enhancements such as Cedega, Wine can even run many games!
If the Windows applications you need to run just happen to be supported by Wine, you won't need to dual-boot or run an emulator. Just run the installers and launch the programs as if they were any other Linux app.
Novell, the company behind the SUSE distribution, recently ran a survey asking people which Windows applications they would most like ported to Linux. Adobe's Photoshop (number 1), Dreamweaver (3rd), and Flash (5th) all ranked very high (you can see the complete poll results here: http://www.novell.com/coolsolutions/feature/16917.html). Will Adobe be porting ...