I recorded part of a chat I had with Gudo Nishijima recently about the difference between doing zazen regularly and not doing it regularly (or not doing it at all even). Nishijima thinks doing zazen regularly is the most important part of Buddhism. Doing it everyday helps us stay "balanced". He compared doing zazen to riding a bike. If we keep pedaling we keep our balance and the bike keeping moving, but if we stop pedaling we end up losing our balance and falling off.
I asked him some other things too, like what he thinks "Buddha" is.
You can download the mp3 file here (lasts about 6 minutes).
Now I'd better go and get a new bike,