Just ran across a very useful little utility called apt-show-versions. It shows you the version installed for each of the apps you have on your server, along with whether or not they are the latest version. Used in conjunction with the apt-cache show command, this makes for a handy little set of tools for working your way through tutorials.
It’s available through the repository on Debian Etch and Ubuntu
sudo apt-get install apt-show-versions
To see everything installed via apt, use the bare command
Or you can use it to check on a single package