You're a SoundCloud user. You love playing tracks on your Mac and love the idea of SoundCloud, but hate the fact that your poor old Mac sounds like a jet engine whenever you play a track thanks to Flash. SoundCloud app to the rescue.
The official SoundCloud app brings "the full SoundCloud web experience to your Mac" allowing you to play tracks directly from your SoundCloud account, search, favorite and create playlists all using a native app. The sounds stream pretty instantly, while tag search is also supported so you can go exploring either through keyword search, through users or tags and save the good stuff for later. You can even drag-and-drop SoundCloud URLs onto the SoundCloud dock icon to create playlists.
The SoundCloud app also supports the built-in Mac media keys, so you can pause and skip tracks like you would with iTunes. Growl support is bundled too, so if you've got Growl installed it'll notify you of track changes.
The only disadvantage of using the desktop app over the in-browser SoundCloud site is that only tracks which have been made available for 3rd party applications within SoundCloud will appear in the app. For the rest you'll have to resort to the website. For me that didn't make much difference as my favorite stuff was all present in the app without issue.
Recording your own stuff is a doddle with the desktop app thanks to the nice big "Share Your Sound" tab in the top left that reveals a massive "Rec" button that you simply hit to record from your Mac.
If you're into SoundCloud, but hate that you have to use Flash, then check out the SoundCloud desktop app -- it's free and works pretty well.