Set the Plays ("Play Count" before iTunes v9.2) of the selected tracks to a user-entered number (they will all be set to the same number). If this number is 0 then the Last Played date of each track will be erased. (iTunes has the ability to "Reset Plays" to 0 from a track's contextual menu.)
Also see New Last Played Date and Add or Subtract Play Count.
Renumber order of selected tracks
Convert selected tracks and export the converted files to a new folder
Perform search-and-replace on text in your choice of tags
Set year of selected tracks to their release date's year (if available)
Copy Comments tag to Description and/or Long Description tag of selected track(s)
Rename selected tracks' Song Names with their filenames (minus extension)