Kurt,
I am in a similar situation. I work in Boston / Cambridge and commute on public transportation from the 'burbs.
My EDC: All carried in a Nite-Izes Pock-it holster
Leatherman Wave
AA Mini-Mag flashlight
Pen
Banadages
Spare cash
My PSK: All carried in a military-style messenger bag
Dougs' Mini-PSK
Emergency rain poncho
Small home-made FAK
Chapstick
Heatsheet emergency blanket
Small pack of kleenex
25' of duct tape wrapped around an old gift card (small and flat)
Spare pair of boot laces
50' of 550 paracord
(2) small aluminum baking pans folded flat (for boiling water)
Spare set of glasses
Set of eyeglass side shields to convert to safety glasses
(2) dust masks
1-liter Platypus water bladder
(2) energy bars
(6) nylon tie-wraps (various sizes)
(2)small 7-hour hand warmers
Work gloves
Headband to convert mini-mag to headlamp
Maps of the city
Copy of first-aid manual
Last (2) items are in a large zip-lock bag
This blends in with the rest of the herd and doesn't draw many looks.
Hope this helps.