Yes, but don't do what the video suggested and plug an analog tape deck into the headphone/mic jack -- that's a GREAT way to blow out the audio chip, which would be an expensive repair. Instead, get an analog-to-USB converter like the iMic, which precludes the need for a pre-amp (which is what can cause the damage to the analog audio circuit in the headphone/mic jacks).
In my case, I needed an RCA to ⅛-inch stereo adapter to plug into the iMic, which then plugged into my USB port. I use Audio Hijack to capture, but you can use any sound-capturing program you want, including the free Audacity (as an example).
That's basically it, unless you want to edit the resulting audio file. Then you drag the audio file into iTunes.