What would you recommend?
I have a Leatherman Squirt E4, which is never the right tool for the job, but always available, and complies with UK knife laws. I also have very good experiences with the Leatherman Wave, but don't carry it around as a matter of course for aforementioned knife-law reasons.
I'm a huge fan of the Leatherman Micra, as it's trivial to have it with basically all the time. I've been surprised with how efficient the screwdrivers manage to be, and at least for me, it covers everything I'd plausibly run in to while out and about (I have a separate one for doing electronics, that includes wire strippers and such, but I've never run in to a situation where I needed that one unexpectedly :))
The tweezers are a bit awkward, but I've used them to remove a number of splinters, so they definitely can do the job (I go barefoot, and having this thing around is wonderful for that alone...)
I have often benefited from recommendations for Things I Didn't Know I Wanted.
Given that Less Wrong is a community of unusually intelligent, critical, and self-improvement-focused people, I suspect we can generate a pretty helpful thread of product recommendations — perhaps even a monthly thread of product recommendations.
Rules: