I don't care about application settings (I'll live without my Angry Birds levels, etc.).
I am playing around with flashing new ROMs and in the process I kind of want to clean house. All the pics are in Picasa, all my contacts, email, cal are on Google. Music is all on my PC and I can copy it again later..
So, will I hurt anything if I just format the SD card?
I notice there is a ClockworkMod folder in there with backup data, which I suppose I don't want to lose, so I guess when I said Format, I really meant (delete everything but ClockworkMod folder).
You can back up and reformat if you wish... as long as you are sure won't need anything else... Just keep in mind that some apps/widgets store data & settings on your SD card which you will lose back up or no back up...
Just hook to computer and copy everything onto a file on desktop. That is what I did. I don't know why you want to format, but you would have access to everything on card just in case.
P.S. I do this anyway just because I don't trust the cloud. It also paid off when my card crashed for no reason, forced format to operate, and just loaded everything back not dependent on apps, etc.