I'm not sure where the lines between modding, hacking, and working are, for the purposes of tool-kit descriptions, so...
Portable kit:
-
144-piece computer toolkit w/case from newegg. The tools aren't the greatest, but at least it's well-organized and portable.
- Pre-Lenovo IBM T61 running Linux (with Win7 and MacOS in VMs).
- Various boot and utility CDs.
- USB to SATA / 3.5" PATA / 2.5" PATA dongle.
-
Hunting knife. I find these more versatile than those utility knives with retractable blades.
-
Greenlee tool pouch containing
--- Linesman's pliers.
--- RJ-11/45 crimper, a nice ratcheting one with cut & strip spots. Trying to cut & strip cat-5 any other way is more trouble than it's worth. :3
--- Punchdown tool.
--- Large leatherman tool.
--- Cheap utility knife for cutting on stuff that will ruin the edge on the Buck.
Other stuff that I generally only use at home/office:
- Somewhat decent soldering station. If you've not experienced this one, you'll be amazed at the difference between a decent soldering iron and a crappy one. This tool is worth spending a little money on, imo.
- Good & sturdy high speed AC dremel tool (single speed) for cutting and shaping metal.
- Less good rechargable variable-speed dremel for cutting and shaping plastic (you need to use a fairly slow speed for plastic to avoid melting it).
- A good assortment of dremel and drill bits.
- Regular hacksaw.
- Scroll saw.
- Decent digital multimeter. Not a Fluke, but better than the $10 analog crap that you find at Walton's Emporium of Sweat-Shop Goods.
- Crappy old worn out dual-channel 40MHz o-scope from the 60s. I don't use this often enough to justify buying a better one.
