Hey ya'll --
We recently had a client request to have "impulse" items available directly inside the cart. I wasn't sure at first if we'd be able to pull that off, but it turns out it's fairly simple.
In the cart template, you can add HTML after the typical ^^cart^^ call, which will get rendered right after the iframe inside the cart.
This HTML can have regular ol' add to cart FoxyCart buttons in it, which will add products right to the cart from within the cart.
Here is a quick mockup we did for them:
Just thought I'd share