Google Music is fantastic. I assume you use an iOS device. GMusic on the AppStore is a fantastic and inexpensive application that you can use to play your music outside of the browser. It is not officially supported by Google, but it is VERY good. The developer is constantly adding improvements and is very responsive with bug reports and suggestions for future releases. I honestly feel it is the best $2 I spent on the AppStore.
+1 for google music, the only thing with that is you must live in the US or use a VPN to sign up, once you have it doesn't matter where you are.
There's also an app called gMusic in the app store which I love.
Recently I migrated to iCloud from my MobileMe account. The only reason I'm just letting it sit unused, is the typical downtime & other issues that prevent it from living up to Apples Claims. It's hard to imagine that Apple still struggles with cloud services, yet perhaps by this time next year it will be improved.
Until then, I'm finding that the other free cloud services are very reliable & filling my needs quite nicely.