OK, here's my answer to my own question.
As a Software Developer, I carry whatever strikes my fancy (Mirage or Point Guard, lately). Usually something somewhat non-threatening, in case I need to masacree (yes, I said "masacree". Arlo would be proud.) a bagel or something. Knife uses at work: mail, fruit, bagels, loose threads, etc. "Hard use", in other words. In past lives I've worked as a stockboy (.99 boxcutters), factory worker (Stanley Model 99 utility knife), deli clerk (wicked sharp counter knives that got professionally sharpened every 2 weeks, and of course the slicing machine
).
My Dad works in telecommunications, and carries a Klein scissor & electrician's splicing knife in a belt pouch, as well as a tiny lockback in pocket. The "splicing knife" (might be a misnomer) is a fixed blade, full size handle with a small, sharp sheepsfoot blade. When I was a kid, he used to make them by hand from an old kitchen knife using a grinding wheel.
When I go out on the party fishing boats this summer, I plan to try out my new (used) CS Ready Edge on my neck, just to trim line, etc. (I let the mates do the filleting). It amazes me that guys that fish all the time and even mates on the party boats don't carry knives, except when dressing out the catch. I saw one mate fiddling with a 10 fuction SAK to get out the blade to trim some line ! A $8 Mora fixed blade or at the very least a one-hand folder would have been so much better. A small necker for me next time (with lanyard !).
