I had a funny experience yesterday that you agavephiles might appreciate. The security guy in this parking lot for a restaurant was totally bored, so he joined me while I was shaking seeds out of the capsules on an Agave attenuata inflorescence. This very plant, actually: The seeds are not nearly as interesting or spectacular as the flowers.
Anyway, I was showing him the seeds (which include light brown duds and black fertile seeds) and he shrugged and told me "somebody needs to water that plant." Because it was quite obviously turning brown and dying. Not everyone even realizes that most agaves die when they flower.
I decided the chances were too high that plant self-pollinated or was pollinated by the americanas nearby to actually save the seeds and plant them.