Your friend isn't insane, there really is a "Lindows", however it's still being developed. Check it out at
www.lindows.com. It doesn't run Windows and Linux on the same computer at the same time, you're confusing it with something like VMware, which allows you to run Windows and Linux together; what it will actually do (hopefully) is allow you to run all your windows applications from linux using some form of WINE. Seeing that WINE currently runs only about 50% of Windows apps, and few of them work as well as they do in Windows, they seem to have their work cut out for them. MS must deem them a threat, however, or why would they waste time suing them?
PS Windows XP's "remote access" might seem like a useless feature on the outside, but don't be fooled! It's actually a malicious trojan cleverly disguised as a useless feature that allows Bill Gates to access all the porn on your computer and then email it to your boss/wife/girlfriend/John Ashcroft. It's wise to be informed about these things!
