I just read a great post on Andrew Leahey’s blog about eight free alternatives to major applications:
1) Windows replace with Ubuntu. Well, might as well make #1 the biggest. For the average user there is absolutely no reason to pay Microsoft for the (wonderful) experience of running Windows XP. So you should pirate it? No, you should switch to a sensible operating system.
Gone are the days when you had to be an experienced computer user to install, much less run Linux. Start around Mandrake 8, the installation process of most popular linux distributions is almost entirely graphical (read: easy). So pick a distribution, and head on over to TuxCDs to download an ISO. (P.S. Some distributions are even willing to mail you a copy for free)
Check out his complete post here. It’s a great list. I agree about the ease of use found in many current Linux distributions. I have been playing with Ubuntu (although I am still using XP for most of my computing) and am very happy with the results.