In online games, having an account logged in and engaging in activity which benefits the account owner is referred to as botting, or less often as zombie. In second life this is often the case with campers. However, the use of libsl allows more and more sophisticated behavior for bots, including copybot and landbots.
More recently bots have been made to provide dance partners in sims, or to fill specific roles in roleplaying scenarios. While controversial, as Second Life moves to mono it seems likely that more bots will be built, and that they will be used as an intergral part of building.