I formatted my harddisk last week and created four partitions. One each for XP, Vista, Linux root and Linux Swap. Got myself a rewritable DVD first so that I dont waste lot of disks. Installed XP first and then downloaded Vista and burned it on the dvd. Started Vista installation and it was very cool. The interface is much better than XP installer. It took approx. 30 mins to install the whole thing. When I finished installing it, I was surprised to see the new Vista interface. It was awesome. Looks like the mac guys are going out of competition. Vista rocks !! But unfortunately, i was not able to intall k-lite codecs. So have to wait for my codec support.
Next I downloaded Kubuntu Edgy 6.10 and burned it. It took me 30 mins to download the 4GB DVD image on my 24mbps connection ;) Pretty fast isn't it. Last time when I booted from the kubuntu CD, it didn't detect my wireless net, video card, sound card etc., But this time everything was up and running from my live CD. Even my NTFS partitions were automatically mounted. So went on to install the actual OS and it was quick. I booted into Kubuntu and installed Automatix and all the apps were installed. But when I tried to play the video, I was disappointed as the playback was choppy. May be it doesn't support my 1680x1050 display. Also the fonts were not to my liking. I liked the fonts in xp and vista much better.
So that's it... now triple booting all three OS's and whiling away my time.
But I am still using XP mainly as it does everything. Once Vista gets all the software problems resolved, there is definitely no looking back...
This is just my experience and not a how-to.