Writing down the note names is only half the problem. You also have to write down which octave they're in (C followed by G could equally plausibly be going up or down, and it makes a difference which), and also specify the note durations and any rests in between. Also you have to make it clear enough that it isn't too much effort for the reader to reassemble it in their own head...

I think I'm currently leaning more towards audio solutions than musical notation ones, simply because not everybody can read music.

(That said, my work PC doesn't have working sound, so audio wouldn't be good for me if someone else posted a tune. Perhaps pseudomonas is right, and my best bet is to use a format which can be converted into audio or a printed score.)