What is Elkano's ItemDB?
It's an addon that will allow you to browse through the items cached in your client with an interface similar to the one used by the auction house. It also allows to browse through the sets provided by LibPeriodicTable-3.1.
So Elkano's ItemDB is just another new addon?
No. It has been around since Dec. 2005, I just didn't open a thread here, yet. So it's most likely one of the oldest client cache database addons around :)