I'm trying to use Powershell more and more, and today I ran into a directory in one of my projects that had a lot of files that needed renaming. Here's the trick on how to do it in Powershell.
I needed all filenames that had a space in them replaced with an underscore so that they would run properly in our batch scripts. In addition, I needed to do this through SVN, and not just a standard rename, so that our other developers noted the changes as well.
After a little tweaking, here's the quick and easy way to do it through Powershell.
[gist]6106435
Note that I've formatted this on multiple lines for readability, simply remove the newline characters so that it is a single line and you can run it at the command prompt in the directory of your choosing.
If you need to tweak things a little, make sure to change the -match parameter on the first line to the character (and potentially string) that you're filtering off of, as well as the replace statement.
Enjoy!