Glad to hear you’re spreading the word about giving blood. The molasses that passes for my blood has made giving sometimes an extremely painful ordeal, but if it helps save a life, then it’s well worth it!
I’ve only transferred a cassette song to my computer just once, but it was super easy. Since I wasn’t worried about fidelity (it IS coming from a tape after all), I used the input jack in the back of my Mac.
All you need is a boom box, a 3.5mm to 3.5mm jack (RadioShack $3), plug one end into the “headphones” port and the other into your Mac’s input port. Go to your sound control panel and change the input device from mic (default) to line-in. Fire up a sound editing program (I use Sound Studio), hit play on your boombox, then hit record in your app and save the glorious results as an aiff file. Convert aiff to MP3 or AAC in iTunes. Done!
You’ll probably have to fiddle with the volume, but it was easy and I now have my incomplete taped from Live 105 version of Cube (2) – Love’s Taboo to rock out to for proof of concept