If you are ever in need of a simple (free) clipboard manager, I recommend you check out Jumpcut. This application works quietly in the background, saving each text copy into an internal buffer. When you want to paste information, click the icon on the menu bar and youll see a list of recently copied text, choose the one you like and youre good to go
Having the ability to copy/paste multiple lines of code, from multiple source files, has come in handy many times.
In the image below you can see the menu bar icon for Jumpcut, along with a list showing my four most recent entries copied into the clipboard.
One other really nice thing about Jumpcut is that its open source. If you are looking to learn about Cocoa development, specifically one which pokes around with some interesting system stuff, give Jumpcut a look.