I use Mixcloud all the time. My iPhone is loaded with mixes from the site. A common complaint heard from users is that they don’t provide you with download links, so I wrote a little app that parses their JSON and gets you a list of the mp3 download links. I’ve also added some features like a list of recently downloaded cloudcasts and a formatted tracklist that you can paste in your iTunes lyrics field. I’ve uploaded it to my VPS and pointed a domain to it.
I’m working on adding support for Soundcloud as well, so look out!