I'm interested in using Google Play for Music, how can I use it in Ubuntu?
Google Music Manager is now (and has been for a while) officially available for Ubuntu (32&64 bit .deb packages as well as Fedora/SUSE).
Download the package which then installs the repository for you from here
I've been running it in Ubuntu 11.04 under Wine 1.3 without any problems. It runs the same as my Win 7 box.
To get it running, first I installed Wine 1.3:
Originally I copied the exe from my Win 7 box but recently I found you can just download from the Unofficial MusicManager for Linux GoogleCode page.
After unzipping to the location of your choice, either use 'wine MusicManager.exe' from the terminal or just double click MusicManager.exe in Nautilus to run.
You can find a lot more info in the following thread on the Ubuntu Forums:
Another option you might want to check up on is the MusicManager Chrome plugin. It looks like it used to work at one point, but has since broken.