Listing of files backed up?

Does anyone have a cookbook method for generating a listing of files 
backed up each time with hdup? It would be very cool to keep an external 
text file showing exactly what files are in the backup, apart from the 
archive file itself. This could be generated separately from hdup, (tar 
tvf <hdup_backup_file> after the hdup backup is run) but that's an extra 
step I'd rather not have to perform.

Any pointers you might have would be great. Thanks!