Florian Pichler:

NoMoreiTunes is an extension for Safari 5 that stops iTunes Web Preview pages and other links to the iTunes store from automatically launching iTunes on your Mac. On top of that it shows a familiar looking bar on the top edge of the browser viewport which informs you that the plugin has worked and let‘s you launch iTunes when you need it.

This is might be my favorite Safari plug-in. It doesn’t do a lot, but it scratches me right where I had an itch.

Update: It seems that I linked to this once before, but it is worth linking to again.