Ordered on ebay a few miscellaneous items for my line of work. Things which I should have with me in the beginning - was embarrassing not having them.
1. Cable/Wire tracer
2. cat5 couplers
3. ps/2 to USB adapters
4. PCI serial ports RS-232
5. Laser Distance Measurer
A tech should always carry these around with him, in addtion to other things I already have.