Grooveshark
Grooveshark is an online music streaming service that has nearly any song you could want. A lot of other music streaming services are blocked out of Australia but Grooveshark has managed to keep it going by paying licensing fees.
It's been my choice over downloading music and using iTunes for some time now because it also has a great recommendation engine that continuously streams music as well as specific stations like 'ambient'.
Another cool feature is user shared play lists which also have some great stuff, and you can also see the most popular tracks as well.
What did happen over this weekend though is that they unexpectedly switched from a Flash to HTML solution with an all new visual style which i'm really loving.
Grooveshark usually resides in a browser, and they used to have an Adobe Air application but now that it's HTML I created a standalone one with something called Fluid.
Together with a custom icon it resides in my dock, perfect.