Marshall
I was looking for exactly the same utility as you when I found your post. I used BAC.COM previously extensively and miss its re Lotus Notes "replication" features which I would like to find in a current command line utility as well. I too have a data/files directory on both my PC and Flashdrive on which I use to keep current files. I now teach at several colleges and keep class/semester related schedules, docs etc on my flashdrive which I access at school. Recently my flashdrive had a hardware error, from which I was able to recover, but it forced me to now copy from one directory to another, making sure I keep track of the time and date file stamps to make I am not overwritin anything important - which is a tedious task at best - I do not have tha amount of data that do you, but have multiple subdirectories I have to manually sync.
As an old DOS expert and recent Lotus Notes Professional, I would like to find a current utility that would meld the features of the two, the DOS BAC.COM command line simplictiy, with the "replication" features of Notes that keeps every instance of a file in sync.
Please let me know if you have been lucky enough to find something.... surely with all the software out there, some one has written/updated this handy utility - especially now it would seem with all the flash drives out there.
Perhaps we can pool our request to get something done.
Thanks
Tom
PC Magazine published a free, simple backup utility called bac.com (from the 1980's, I think) for DOS. It copied files from one drive to another, but did not copy files that had not changed. It had a few (very few) bells and whistles, but I used it regularly and it was very serviceable. Today, however, it cannot handle large files or longer than standard DOS filenames.
Does anyone know of any free or inexpensive utilities similary to bac.com? All I need is to copy files from my had drive to my flash drives for backup, and avoid copying the whole thing (three hours!).

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic