[Selecting every other pixel in an image?]

Damn, I wish I could tag 2 suggestions as the solution. I tried the ideas from MJW and Red ochre. Both solutions worked exactly how I wished they would, but I will say that the Scintillate was much quicker and easier. Thank you both for your wonderful suggestions! I wasn't expecting such good answers so quickly!

[Selecting every other pixel in an image?]

I've recently started working with a specific concept that I really like and I just want to know if there is any tool or method for doing something that is otherwise very time consuming. What I'm trying to do is select every other pixel in an image so I can invert them. I've been doing it manually by selecting every other pixel in a small area and moving that selection shape around until I have finished inverting every other pixel. So none of the selected pixels are immediately bordering each other, and they only touch diagonally. I know I'm probably asking for a lot but I'm hopeful that there is some way of doing this faster.