This regex takes any file that starts with a name in format FirstName LastName and changes it to LastName, FirstName. It's a variation of the regex found in the BRU help files. Very handy for sorting mp3's by artist, where you'd rather have all your Brian Eno mp3's grouped with the E's rather than the B's etc.
Match:
^([A-Za-z]*) ([A-Za-z]*)(.*)
Replace:
\2, \1\3