Conference Production question...

Hey Cows,

I'm partially in-charge of the production of my company's annual conference this year.
I've created various video content and slideshows to display at certain times throughout, and there are, say, Powerpoint presentations that keynote speakers will be using, as well.

I'd like to be able to cue up and sequentially roll the various presentations (i.e. the conference kick-off animation video clip, then a conference-themed still image, then into an image of the keynote speaker, then into the speaker's Powerpoint) all without the audience seeing anything change on the big screens. You know... all professional-like! In the past, it's been a series of blanking out the projector, cuing up the next piece of content, then un-blanking the projector. It's messy and well, you can imagine what it looks/feels like...

I've done a lot of research today and I cannot seem to find a solution other than Wings, which we just can't get right now. Is there anything else out there (hardware or software) that can help me do this?

Thanks!

- The Foonshoe