My laptop bag always contains a small TSA-safe survival kit, with other things added when I'm not flying.

• first aid pouch, including boo-boo kit, small OTC med kit, and small trauma kit, including Combat Gauze, SWAT-T, gloves, duct tape, Z-pak dressing
• flashlights: a NiteCore EC20 (2xCR123A) and an iTP EOS A3 (1xAAA) on a neck lanyard in the main kit, a Preon 2 (2xAAA) in the admin pouch
• spare batteries (2xAAA and 2xCR123A)
• small amount of cordage
• Fox 40 Micro whistle on a neck lanyard
• more duct tape (separate from trauma kit)
• Aqua-Pouch (1L)
• small sewing kit
• button compass
• a couple rubber bands holding together a few bobby pins and paper clips of various sizes
• sunscreen wipe
• small dual-band ham radio transceiver with earbud and antenna, suitable for listening to broadcast FM as well as ham use
• mini-Bic in a keyring holder that protects the valve and is itself flammable
• spare pair of sunglasses (when I'm wearing my contact lenses)
• spare pair of prescription glasses with magnetic clip-on sunglasses
• small hygiene kit

All this stuff takes up surprisingly little room and weight. The TSA never gives me any hassle about any of it. I carry a keyring Leatherman Style PS when I'm flying which gets inspected about one out of every three flights.

Laptop bag items used for work that might be useful in an emergency:

• smartphone/tablet charger (this is a place where I see too many people buy cheap and later regret it, mine is a good one)
• cables for everything you imagine and some things you probably don't
• compact travel power strip (THIS is what you use to be a hero at the airport)
• admin pouch that includes a notepad, pens, markers, and the aforementioned Preon 2 flashlight
• laptop and power brick

When I'm not flying, I also carry:

• LM Wave
• Screwdriver kits, large and small
• spare magazine for my carry pistol, to supplement the spare mag that I carry on-body (only where legal)