Okay, So I made the choice to multi boot my current XP PRO SP3 with 98SE And Whistler 2267,
but What I want to know is if any one else has installed a beta as their main OS or as a Dual or Multi Boot system, and
if it is a good idea or not?

First off, it is an bad idea to run out-dated Beta's on your system anyway.
Plus that you loose the space on the disk if you double (in your case triple boot).

You could with an current Beta of Windows (which are not leaked) but not recommended since it could make your system unstable.
Also mind that if you connect them to the internet they can't be updated, and no AV supports it or installs the wrong version.

Its like:
''oh cool, I run an version of Windows I am ''geeky'' and super duper, but why won't stuff work?!?!?! and why am I infected with virusses?!?!'' --> It is maybe cool in the beginning but then not anymore and for the other 2, either the OS is outdated but cannot be updated or AV's do not work.

That is why you always see with the Microsoft EULA of an or other in development programs that you musn't use it as your production system (eg also called your main rig where you do all your stuff), it could possibly crash, make your harddrive unreadable/crashes or (in case with Windows 7 Beta before the patch) make your MP3 files unreadable.

I suggest you just stick with your Windows XP Professional with Service Pack 3 and then install Microsoft Virtual PC 2007 with Service Pack 1 and/or VMWare Workstation 7.1.3 and install in there all you're 's and other OS'es.

So an short answer:
No.

Took yor advice and just stuck with 98 and used
A virtual hard drive instead. Good advice is good.

Thanks

I am amazed you're using a 12 year old OS...

Unless you're referring to Windows 98 as a whole, Windows 98 Second Edition is only eleven years old, since it was released in May 1999, having been compiled on April 23rd that year.

No, I haven't, because it's utterly useless and in the end you get a unstable OS which has possibly broken features, is unstable, in insecure, etc. It's a security risk to run a beta as a OS (especially a build that early...)