File Renamer 

Rename all your files and folders, with a lot more options. You can batch rename files, extensions, add or remove strings, numerate filenames, replace strings, and more.. Suports Drag and Drop and has 'undo' function.
file renamer name date numerate batch extensions string convert characters replace directory free freeware

Renamer + random 

Full featured batch file renamer. This is the only renamer that can add a random number to the filename. This is very useful for webmasters who want to randomize the order that pictures appear. Also had limited regular expression support. Extra fast.
graphics tools file utilities webmaster tools free software random rename pictures order