question on choices using bootcamp part thru a vm

New 10.7.1 mbp with 750 gb drive 400 gb to OS X and 350 to bootcamp partition running win 7. Actual space used by win 7 in the big bootcamp partition is about 100 gig ( lots of data for various reasons ).

I have 8 gb of ram. While the macbook pro does a really nice job running win 7 native I want to start getting away from that. Been backing up bootcamp using win 7 recovery creating system image on external drive.

I am more than a little confused about what options I might have to keep the bootcamp partition around as-is but also being able to run the bootcamp partition thru one ( of several possible ones ) from OS X.

Can I really use under 10.7 one ( or more ) of Virtualbox/VMware/Parallel software vm options and ( somehow ) point them to the bootcamp partition directly?

If I do that will there be changes made to the bootcamp partition that will prevent me from restarting and running win 7 native?

Or do I have to create a system image of the bootcamp partition within the space I have under OS X?

Any hints/tips/clarifications appreciated!

For me it would be nice while my learning ramps up to be sure that my bootcamp partition is still safe and workable either directly or via vm from OS X.