How do you handle multiple users from the same "client"?

[JohnnyHeavens]

How does eveyone handle multiple users from the same group or company? I would like to be able to list notes or history by the client and not just by the user.

For example, is there a way to track users that are all from the same company without make seperate queues?
Company/Department A
User 1
User 2
User 3
Company/Department B
User 1
User 2

Thanks!