If you download from RapidShare frequently then this post might be useful for you. This plugin is very useful Firefox plugin that can be used to detect Rapidshare Happy Hour all time. The Rapidshare Happy Hours plugin is compaitable with FF3.0. It is helpful for users those who use free account on RapidShare. Plugin notify you with the popup box whenever HappyHours available.
Download Location: https://addons.mozilla.org/en-US/firefox/addon/7353