Looking for ideas for "overflow" seating.

I'm looking for ideas for extra overflow seating, which hopefully will be lightweight, somewhat comfortable, and of course cheap. Pictures would be great. Chairs that are stackable would also be great to save space when not being used. Thanks.

Thanks Sevker, I read that thread. But I can't find any of those chairs on their websites. Does anyone know if they're not available anymore?

Is anyone using the video rockers from Walmart for $24? Are they any good? Thanks.