Depending on which data you double-click in the password list (main window),
different actions of the entry are performed.
When you double-click onto the 'title' field of an entry, its edit
dialog is opened.
When you double-click onto the 'username' field of an entry, its
username is copied to the clipboard.
When you double-click onto the 'URL' field of an entry, its
URL is opened in your browser.
When you double-click onto the 'password' field of an entry, its
password is copied to the clipboard.
When you double-click onto the 'notes' field of an entry, its
notes are copied to the clipboard.
Similarly, when you double-click onto any of the time and UUID fields,
the contents of that field is copied to the clipboard.
Global Hot-Key To Restore KeePass Window
At startup, KeePass tries to register the global hot-key Ctrl-Alt-K to
itself. If no other program has reserved this hot-key already, it'll restore
the KeePass window when you press the combination.
If you have multiple instances of KeePass running, the instance that was started
at first will be restored.
More KeePass Application Icons
If you want more application icons (for example because you want to give all
.kdb files an icon like the KeePass main icon, but don't like the blue one),
then download the latest source code distribution from the KeePass website
(the file usually looks something like KeePass-X.XX-Src.zip).
Unpack it and you'll find several different icons in the "Ext/Icons"
directory.
These icons are not included in the binary distribution because this would make
the application file too big (adding 400kb just because of icons?).
Drag&Drop Fields
You can drag&drop all fields of KeePass entries into other windows. Here's
a screenshot illustrating this: