Or make another PSD with the logo/design/whatever on a separate layer - you just use the Move Tool (hit the letter "v") and drag it from one doc to the other.

Many people like the keyboard commands of copy/pasting - more often than not, I just click, drag it to another doc, and let go - done. Taking the time, to make your selection, hitting the keys, clicking on the next doc, hitting the - I'm already done and moved onto the next parts. When you're copying to a mask, use the keys (doesn't work any other way) - when you just wanna get one element (or an entire image) from one doc to the other - click and drag and let go.

You can also make it with a number of layers - each one a logo for a specific sized image. You label each layer the image size it's supposed to go on, hit the letter "v"...

Hope this helps-

-Lew