Whenever you go to get a file on rapidshare it does a countdown until you can get it. If you get the greasemonkey extension for firefox and install these scripts, it will skip that time (and also skip the page that says, "Premium/Free" and just go to the download). There are scripts for other sites too.
It might also beat the time limit, not sure link link
oxyshare: link
uploading.com: link
turboupload.com: link
sharebigfile.com: link