I've actually been doing this for a while, and I find it really useful. My list of sub-agents is as follows, ones more likely to be endorsed marked with a (+):

*Me (executive)

*Internal Critic/devil's advocate (2nd executive who takes the opposite position from the first)

*Rationalist/scientist (+)

*Ambition (+)

*Conscience (+)

*Optimist (+)

*Cynic

*Arrogance (frequently rebels against endorsed entities/positions)

*Inner adolescent/sense of humor

*Immediate desires/drives (akrasia, hunger, libido, etc.)

Rather fragmented, but they are hardly ever all there at once. Cynic and Optimist don't show up at the same time, Conscience is often played by one of the executives, and Adolescent rarely has anything to say.