What is the best way to upload a folder to a website?

I need an easy way to allow users to upload multiple files at once (ie I need to allow a user to upload a folder). I do not wish to put the burden of zipping on the user.

I would prefer to avoid Flash or variants if possible. I'm looking for a straight javascript / HTML solution if it is possible. Please note, this rules out the answers at: What is the best client side browser library to upload multiple files over http?.