In TextMate there is a feature called "Go to file" that is used for file navigation. It is a box where you type the name of a file in your project and it will use fuzzy matching to generate a list of candidate files from which you can select.
Other editors have this feature, but they each give it a different name:
Vim fuzzyfinder
Emacs fuzzy-find-in-project
TextMate Go to file (fuzzy)
Eclipse OpenResource (not fuzzy)
Eclipse GotoFile (fuzzy)
Komodo Go to File (not fuzzy)
Netbeans Go to file (not fuzzy)
Does jEdit, Geany, or Ultraedit have this feature?