I've installed Apple's Boot Camp, which lets my Intel-based Mac boot into Windows. To do so, you hold down the Option key at startup, and then select either the Mac or Windows partition to boot from.
When at the boot volume selection screen on my 17" Intel iMac, I found I was able to switch between the available boot volumes, and select the one I wanted to boot from, with the Apple Remote. Note that my remote is bound to this specific Mac -- I'm not sure if that effects the feature.
[robg adds: Same thing worked here on the Intel mini...]
Mac OS X Hints
http://hints.macworld.com/article.php?story=20060509103441213