Downloading sound files with safari

With Firefox I use Download Helper to download the mp3 that is in certain videos, you tube, flash files etc, they are downloaded usually as a .flv file which I easily convert to mp3. It is a simply tool bar add on, one click and the sound file is downloaded

Is there a similar program like Download Helper for Safari? Or if not how can I download the track being listene dto easily with safaari.

The lack of add-ons with Safari is the reason I used Firefox. You would think with all the apps etc for etc they would do something similar with Safari. iphone