Is there a way to switch output sources with speakers plugged in?

I've seen a few different posts here are there and they aren't quite what I was looking for, so I'll explain all the details of my situation to see if I can find a trick for it

I want to run an 1/8" stereo cable from my iMac to my home audio receiver to play songs from iTunes through my home stereo system.

However, I don't want to have to constantly plug/unplug the stereo cable from the iMac repeatedly, every time I just want to play a game, or any other app that uses iMac's internal speakers. I'd like to find a way to switch the output between the stereo output plug and the internal speakers while leaving the cord plugged in the whole time so I don't wear out the socket.

Does OS X Leopard offer a way to do this?

I apologize if it's too simple of a question, as I'm new to the Operating System. Let's just say I'm not jazzed about submitting to the inefficiencies of Windows Vista

Yep, that's kind of a convoluted way to do it. However, setting up a switching system to avoid plugging, unplugging would be just as bad as far as wearing things out - including you.

What I suggest instead, is set up a wireless system to your stereo receiver. Do some research in this forum and others for "Airtunes" to get some good ideas. It will mean spending some money on wireless equipment like this unit from Apple: Link

There are folks who post here that I'm sure will be able to help you out about setting up a wireless music system. Good luck.

Regards.