Like ashley says, a few mates and a microphone in which case a script is vital. You could use a marine band radio as a source.
Either way, plug the source (mic or radio) into the appropriate input on your PC, run something like "Audacity" (a freebie sound processor), and click the red button to record. When satisfied/bored, stop recording, edit out the bits you don't want, play with the levels, export the result as an mp3 file to save it somewhere convenient. Its a lot easier to get a good result than fiddling with tape, if only because you can see where the bits that you want to edit are.