A lot of the networking equipment and PC diagnostics and repairs and such are in my kit as well (I run a retro-briefcase rather than a backpack or bag though).
Something that is, to me, obvious in it's lack of appearance in the list is a LiveCD of Backtrack, and a LiveCD of a windows recovery (I use UBCD). The amount of times a PC Repair job has turned into a "I forgot my password" or "I have a virus and can't rebuild my machine because i lost the disks" which can be fixed via a BT boot or an Avira scan is phenomenal.



Also for the coax connectors, get the kind that have the colored plastic that locks the cable in from the cable side, not the kind you have to crimp the sides. These seem to me to work a lot better.
, we all got a laugh when we got these shipped to us. While I wouldn't say a "must have" they actually have been useful for places that had low light visibility.

