I've just purchased a front projector which allows me the option of turning off the progressive scanning and 3:2 pulldown for film-based sources in my projector...if I were to buy an external scaler/processor like the DVDO iScan, could I use that to perform the 3:2 pulldown, or does the 3:2 pulldown HAVE to be done after the video signal reaches my display(in my projector)?...I would appreciate any help I can get...My projector is a Sanyo PLV-Z2 and.I will only be watching Blu-ray and standard def DVDs...Thank you all in advance.

I may be missing something - there wouldn't be a need to manually disable progressive scanning or 3:2 pulldown if you are sending your projector a signal that is already 60fps and deinterlaced, which can be achieved with any player (doesn't require a processor like the iScan).
As far as I know, 3:2 pulldown is rarely handled by the display device. It's most often done in the source player, with standalone video processors being the next most common place.

If the projector can accept 24p, your Blu-ray player may be able to output the original 1080p/24 signal contained on a Blu-ray disc without any processing. I don't know how many players are allowing that with standard DVD's, though, and there is still the question of what the projector does - if it is operating at 72Hz or 120Hz, it can simply repeat each frame three or five times to yield the original 24fps video.

Thanks Gonk...My Denon DVD 1910 has the Faroujda chip for deinterlacing, but I wasn't sure if it was performing the 3:2 pulldown at the same time though.

Yes, the Denon is performing 3:2 pulldown somewhere.