Don't you hate it when you get that perfect shot and it is ruined by a big red zit, or a cookie crumb you were saving for later. Well, I know how to fix it, and I will let you in on my secret weapon. It is called the healing brush tool, and you can find it in any version of Photoshop CS.
Because I am a nice person, and I don't want to embarrass any of my friends or family by using a picture of them with a zit, I will offer myself up for demonstration (ignore the crazy man on the left). Here is an old picture of me with a giant zit or two on my chin. Do you see it, it is glaring at you in all of its redness. (Sorry about the pixelyness of the photo, old camera). There is also a scar on my forehead and several small zits I will try to get rid of, but focus on that giant one on my chin.
Now we want to zoom in so that the evil blemish is clearly visible. Choose the healing brush tool in the tool box, it is the one that looks like a band aid, or simply press "j".
Now, choose a brush size that is just a tad bit bigger than your blemish. While holding down the alt key click somewhere nearby that doesn't have a zit. Release the alt key and then click on the zit. Zap, it is gone and the area is blended in nicely with its surroundings.
Here is the image with the zit removed. My scar is gone too, and so are some pesky little zits, see?
Isn't that a fun trick, now you never have to wear makeup again. Yikes, that could be scary. Have fun :)