A year ago I approached a designer on Dribbble about using his design (http://dribbble.com/shots/595176-Hype-Machine-Mac-App?list=u...) to learn Objective-C and maybe create a cool way to use the Hype Machine on OSX.
We've come a long way since then. Glenn (@glennui) has done some incredible work on the design (check out the iterative improvements: https://s3.amazonaws.com/f.cl.ly/items/1O1Z193I0i0J1y0R2a3X/...) and we think it's one of the best ways to find new music out there.
If you're not familiar with the Hype Machine, here is a quick summary of what's going on http://blog.plugformac.com/post/63340578035/introducing-plug....
We just released a public beta. It's free during the beta, so check it out and let us know what you think.