Why isn't agar agar more popular?

For those unfamiliar with it, agar agar, or just agar, is similar to Jello, but without the annoying rubberiness (being able to shimmer and shake makes for a nice play thing but not much of a food). For vegetarians, agar has the advantage of being derived from a type of seaweed. I find it mixes well with fruit and serves well as a layer of a parfait. Try doing that with Jello.

As a side note, both Jello and agar are what chemists refer to as colloids. I remember a high school science teacher introducing us to colloids by bringing in a plate of Jello. Colloids are mixtures of two substances where one substance dissolves only part way into the other, maintaining fairly large particles, so the combination has characteristics of both. Gelatins are interesting because they are not quite liquid and not quite solid. Other examples of colloids are paints, aerosols and sludge.