Renaming files in Windows Explorer is somewhat slow - select, F2, type a new name, select the next file, and repeat. I thought it would be cool to instead use a spreadsheet interface - where pressing Enter drops you down to the next line.
So, I wrote RenameCells, a Python program for quick renaming. I also added features for batch renaming like Rename by Pattern, Replace, and Regular Expressions. You can see all of the changes in a grid before you press Rename. The grid interface also lets you copy and paste from Excel or another program. See the tutorial for information about all of this.