Every now and then, there is an idea executed on the internet so well, it could make almost any concept look wonderful. But what if the concept was great to begin with AND was executed flawlessly? This is rare, but a friend of mine turned me onto such a case: Grooveshark.

Grooveshark allows you to search for and stream basically any song in the world. How this is legal, I don’t know, but it works wonderfully. The interface has animation and smoothness not seen in many desktop, let alone web, apps. And its usability rivals iTunes.

I have a feeling this website could replace many iPods at work, having a phenomenal selection with no setup, installation, or signup required. Just logon and start listening.