I came across a cool little tool called Nuvola that is a wrapper around various cloud music services such as Grooveshark and Google Music. It not only makes them into full applications but does things like add support for scrobbling and multimedia controls. I quite like having my web apps appear as full applications and use the "Make Application" function in Epiphany to do it quite often. That way typing "gma" will either switch to the running app or start up an new Gmail window from anywhere on the desktop and I find that regular desktop controls like alt-tab are easier to manage than tabs in a browser for apps that I am using regularly.
This rambling post does have another point to it though. A lot of the cloud music sites still use Flash to play the music. Flash has always caused problems because it's closed source and so people can't fix all the niggling issues. Instead we have hacky work arounds. I present a stack of them here.
When my laptop is docked at work I have two sound cards and for the most part it works okay. I can switch between them without any problems and use my headphones or speakers that are always plugged into my dock. When I tried Nuvola it refused to send the sound to the dock sound card and was not even showing up on the list of apps using the sound card.
TL;DR: apt-get install libasound2-plugins:i386
I will go into some more detail now. Nuvola is quite new and used the GTK3 toolkit. Flash is quite old and uses the GTK2 tool kit and we are waiting on Adobe to update it. So in the mean time we have to make them play nice together. To do this we use nspluginwrapper which runs flash in it's own process space. There is a howto on the Nuvola site for installing a compatible version of flash and that should at least get you flash running and some sound coming out.
Next up is the problem that this wraps an i386 version of flash and if you are running on amd64 like I am then it needs some extra libraries to make it work. To do that you need to setup multiarch support. Simply run dpkg --add-architecture i386 and run apt-get update as root. You can then install the asound plugins for i386 so that the Flash plugin can talk to pulseaudio. Run apt-get install libasound2-plugins:i386. Restart Nuvola and you should be good to go.