Windows/OSX/Linux

Ok so I didnt really know what section to put this in because it is about all three big OSs. Basically the AAO is my toy. I dont like messing around with my desktop so I mess with this. I just installed a 500GB Western Digital hard drive and I want to set up all Windows 7, OSX, and Ubuntu Netbook Remix on it. I was wondering which order to install these. I was thinking OSX then Install Windows 7 in bootcamp then install Ubuntu because Ubuntu usually catches all my bootloaders, but what if I decide I don't want OSX then do I have to reinstall Windows. I already have Windows 7 on it so to have to reinstall it 2 times would be a pain.