I recently had a headphone jack die on an older machine at work. It's old enough that I don't want to repair it, but it still works fine. Using the Plugable USB audio adaptor, I was able to still hook up external speakers or headphones. It plugs into a USB slot, and then allows you to plug in a microphone or speakers. It supports Mac, PC, and Chromebooks with no driver needed.

Get it on Amazon for $7.95