Update. Looks like a few like the idea so I made it so you can make your own format string to add to the file (and Prepend to file). See the ReadMe.txt for format options. Download from first post and see updated screen shot.

Sorry about the spelling, It's not my strong suit. :-)

Since I write a lot of code and have tone of versions and files and archive a lot of files. I used to manually add the date to the end of files, but I started doing it so much I made an app for it. This adds an AppendDate item to the context menu of files. When you select it, it adds the current date to the end of the file name (i.e. MyFile_20120511.txt) You can change the date format in the settings dialog. Hope you find it as useful as I do.



[UPDATE]
Now works on folders

[EDIT]
Made it so you can make your own format string to add to the file. See the ReadMe.txt for format options.