Pack everything you need...
...but pack light. We reduced our loadout from about 380 pounds to 73 pounds for a full kit by dispensing with tools and bits we haven't used for 15 years and careful tool selection. We were afraid that productivity would go down because we'd find that we actually needed the whatchamacallit, but the opposite has been true.
We can do more with less tools, deploy faster, and do it in some tight quarters. Beter still, rather than use trucks averaging 18MPG, we use smaller vehicles averaging 33MPG. It has been a win all the way around.
As far as paperwork and a laptop is concerned, We upgraded to a netbook and bluetooth printer some years back. Consolidating CRM and billing and putting that on line has been a major benefit. The tech only needs to print the bill if the customer wants, otherwise it's emailed. Weight savings went from 26 pounds to 10.
We just upgraded to the Motorola Xoom for field use. We are still working some bugs out, but it looks like this is going to be another leap forward.
