I'm going to attempt my first greenscreen project in Vegas later this week and am looking for some cool animations to lay in behind my live action footage (no more than 30 sec each though we need several of them). Right now the theme is pretty open, but I could go with psychedelic shapes/animations; or something simple that you might see for kids [though it's not a kids project] - a countryside with hills, trees, blue sky, sun, or a cityscape - taxis, streets, cars, tall buildings, parking meters. (It's an SD project so standard def animations are fine.)

Any ideas where I can find some cool animations on-line? (We're a "no-budget" production so free would be great :-))

I highly recommend the Digital Juice Jumpbacks.
They constantly have sales on so the price is very reasonable.
For example, you can get any 3 Jumpbacks until midnight Monday (Apr. 9) for only $79 (regular price is $99 each!!) so it's a great deal.
Check them out at http://www.digitaljuice.com/

We have many SD animations at $15.00 each.
HD animations at $29.00 each.
We have some free clips available.
You can e-mail me for info.
Digital Juice is great and I have used many of there products but
you must buy entire discs which could stretch a budget.....