How to Backup (and restore) your wallet
Backup your wallet is one the first thing you must do to put safe your coins.
But too you need protect it with a password, go to Settings / Encrypt wallet and insert your pasword.
Once you have a good password, all you have to do is save the file wallet.dat.
You can find it in:
Windows: C:\Documents and Settings\YourUserName\Application data\Bitradio
Mac: ~/Library/Application Support/Bitradio/
Aditionally, in that location exist a folder called backup where you can find copys of your wallet.
Copy the file wallet.dat in a usb, in your desktop, mail you, in google docs, put it everywhere... if you have a strong password, you can copy where you want, and recover it when you need.
How can i restore my wallet?
Just replace wallet.dat with your backup.
Easy, isn't it? : )