The number of backup files 001..002..003..etc etc in the revit folders was causing me a little grief as firstly, I would from time to time inadvertently open a backup file instead of the main model and secondly, the exceedingly large number of backup files (for me, the number of backup files was about three times the number of model and family files!), slows down windows indexing and has a bit of an impact on searching speeds.
Having read a number of previous threads on this issue, I came across http://forums.augi.com/showthread.php?t=56491 where tobie provided a small simple bat file remove all backup files.
Attached is a slightly modified version of tobie's bat file (I changed the identifier from 0 to 00 as I sometimes use 0 in file names).
Simply place the bat file in the parent folder for revit and run the file - it automatically runs through all sub folders of the parent.
It works a treat, all credit to Tobie