We have a bail out bag, similar to the maxpedition bags. We have a swag, flashligh, long needle nosed pliers, pens, scissors, hemostats, log books Nano-large, expandable mirror, expandable magnet, spare magnets, and anything you can think you would need to repair or do maintenace on a cache. We don't use half of it but I am a rather have it and not need it than need it and not have it type. We also use a GPSr and a cell phone on most caches.
The bag is the key because it has lots of pockets for all of the things you may need