See mathrawka's reply (I haven't test it though)

BTW, I just ran memory of my server into swap with this:

    $ dd if=/dev/zero of=2g bs=1M count=2048

    $ curl -F "2g=@2g" <myresource>

(EDIT: explanation, this creates 2g file then uploads it <myresource> as a file upload -- multipart mime. @ sign just insert the named file data into the form)