Welcome aboard,
I carry the usual things like a notebook & pen. Department requires a whistle on lanyard with cuff key in left shirt pocket. Metal mirror in right shirt pocket(useful for looking around/under/over when I don't want to expose my knoggen). Bandanna in trouser pocket. Compass on watch band. Laytex gloves inside zippered shirt next to vest. H.D. aluminum foil, dental floss, wire, bandaids and needle in wallet(foil, wire and needle made it through airport checkpoint last year) and extra cash. P-38 on key ring. I keep my keys in my pocket and use seperate ignition key for vehicle. This keeps me from locking myself out of the car when I have to leave it running (bad thing to have to call headquarters for your own lock out). Case of bottled water and a couple of MRE's in vehicle along with first-aid kit, flares, blankets and extra large trash bags to sit the nasty drunks on.
Hope this helps. Glad you posted this as the other replies have got me thinking.