13.04 has a nice tool in the repositories: "undistract-me". It will inform you about when a command in a terminal in the background finishes.
To enable it:
1) sudo apt-get install undistract-me
2) open Terminal, in Terminal: “Edit->Profile Preferences”, and select “Run command as a login shell” must be enabled in your terminal.
3) close Terminal, and open a new Terminal
After that, you will get a popup *if* the command is running in a Terminal that's in the background
More info on http://www.cnx-software.com/2013/03/...ands-in-linux/