I put up with dual booting for years before dedicating one computer to each OS I wanted to run. That does take up desk space though.
My standard response to 'wouldn't it be cool to dual-boot?' is 'No.' Any time I actually did it I ended up on one operating system, including:
1) small Windows 98 partition to run one game -- it ended up being wasted space because I could never be arsed to reboot.
2) dual-boot Windows & Linux... ended up spending all my time in Linux, going over to Linux, then I had a severe attack of post-flu depression and crawled back to Windows because Linux was too scary. This was years ago, so I had no help with Linux like a local user group. It effectively meant I was my own sysadmin, and I wasn't up to it when feeling less-than-optimal.
Am now a happy Mac user because it has The Friendly when I feel Nervous and The Unix for when I feel Intrepid :-)
I still think dual-boot requires a lot of discipline, and I tend to only reboot once a week or less...
Regards, R