Several different IE in one bottle

Hello! I would like to finally find some solution that allows you to run several IE for debugging at once: for example, IE 5.5, IE6, and, accordingly, IE7. While the solution to the problem is not visible. Could you help me? Thank you in advance.

UPD: Multiple IE , IETester , and, in the case of Vista, Innotec Virtual Box . Many thanks, habra people. :)