I also use Keil. Microsoft SoureSafe is on my list of "Things I really ought to learn when I get more time."
My current version control goes like this:-
1. Add a file called "version.txt" to the project.
2. Keep a working 'MyProject' directory and a 'BAK' directory.
3. Everytime I either reach a milestone in the development or fix a bug I add a couple of lines to versions.txt giving the date and a short description of what I did. I then copy the whole project directory and paste it as a subdirectory into the 'BAK' directory. Once pasted I change the name to include the date (e.g. 'MyProject260303'

That way whenever I need to backtrack I can just pull out the saved directories one by one till I find what I'm looking for and compare the verions.txt files.

Hope this makes sense. Any coments other ideas?

Paul