Well, this time is not a metaphor involving agents or whatever else computer science-related... but I guess it will inspire one soon;-)
My girlfriend tried to comfort me from having blown 32 candles with a gift that is mesmerizing me: it's a glass sphere, about 12 cm of diameter, full of water, algae and.. living shrimps! Tiny, red shrimps, very different from the ones I'm used to see while snorkeling in Camogli: they're supposed to be an Hawaian breed, that lives in independent puddles. Well, that sphere is meant to be a completely independent ecosystem, with a life expectancy of 3 years (they claim that it could reach 12, though) if you're just so kind to provide it with indirect light and a reasonable temperature (13-27 C). They have a nice website here.
I REALLY like it, thank you dear!!!