Which other Outlook most recently used (MRU) lists can I edit?
Outlook stores the MRU lists for the Standard toolbar's Find a Contact box and the Tools menu's Find command in binary format. You can't edit these lists, but you can clear them. To clear the Find a Contact list, delete the HKEY_CURRENT_USER\Software\Microsoft\Office\10.0\Outlook\Contact\QuickFindMRU\QuickFindMRU registry entry. To clear the Tools, Find list, delete the HKEY_CURRENT_USER\Software\Microsoft\Office\10.0\Outlook\Contact\StripSearchMRU\StripSearchMRU entry. Outlook will recreate these entries the next time you use these Find features.