2in1

I've not read through the whole topics and threads, and this would be my first post. By surfing and searching through the net, i couldn't find any solution to have a Vista + XP multi-boot dvd. So i thought leave a post here and have some help from the pros. is it possible? and if so how? i'd like to have XP (x86 + x64) and Vista (x86 + x64) all in one dvd (dual layered) which makes it 4 OS in 1. Thanx in advance