Is the eukaryotic cell a colony?

I build modular, self-organizing, docking robots (or actually their control architecture). From that point of view I am really interested in the computational power of an organism versus swarm organization of robotic modules. I write about it on my blog, entry 14 and 15. I like also the work of Tony Prescott for example about the application of primitive nervous systems on robots. Do you guys now what the advantages of a (multi-cellular) organism are? Why should I want to have a robot organism rather than a robot swarm? Are any of you interested in defining a scenario in which organisms and swarms emerge?