Basic walkthrough (no other goals):
Get all the items you can see except drinks, then:
-Give the Penicorn to Jeff
-Use the spanner on P-Bot to get some pot, and give that to Bob
-Just talk to Swain, he's already ready to party
-Get a ginger ale from the drinks machine, use the carrot on it, and give that to Mike
-When Mike's gone, talk to Afro-Ninja, then Tim, then give Tim the cash and Afro-Ninja the pick
-When Afro's gone, talk to Tim again
-Get a Miller from the drinks machine, use the bleach on it, and give that to Luis
-Go into the meeting room
-You win.