Klipper can perform actions on the contents of the clipboard, based on whether they match a particular regular expression. For example, any clipboard contents starting with "http://" can be passed to Netscape or Konqueror as URLs to open.
To use this feature, just copy a URL or filename to the clipboard. If there is a matching regular expression in Klipper's list, a menu will appear showing you the options you have (e.g., open URL in Konqueror, open URL in Netscape). Use the mouse or keyboard to select the option you want, and Klipper will run the program you have selected, opening the address pointed to by the clipboard contents.
If you do not want to perform any actions on the clipboard contents, select "Do Nothing" on the popup menu to return to what you were doing before.
Actions can be disabled completely by clicking on Klipper (or pressing Ctrl-Alt-V) and clicking on "Actions Enabled" or by pressing Ctrl-Alt-X.
Clipboard contents which match a regular expression can also be edited before performing an action on them. Select "Edit and process again" on the Klipper popup menu, and you can change the clipboard contents in the dialog which appears, before clicking the OK button to run the appropriate action.
Pressing Ctrl-Alt-R shows the popup menu to repeat the last action which Klipper performed.