First, I owe everybody an apology for not keeping up with the responses here. No excuse, but it's been that kind of week (first week on the new "job", etc.). I do appreciate all the suggestions.

For years I carried a CRKT Sampson's KISS (arguably a 3 inch blade, a little larger than a standard KISS) clipped to the back side of my Palm belt case (which rode horizontally). That was a bit smaller than I'm really comfortable with for a primary knife, but it was a lot better than nothing, it was almost always with me, and well concealed that way. However, some months back I upgraded from a Palm 3xe to a Palm Tungsten T, which is consideably smaller, and the case not large enough to hide even that small knife.

My currently preferred "weekend" carry (if I'm not on the water) is a Gerber Harsey Airframe (plain edge, black handles, 154cm, "1 of 1000", yadda yadda) which has a 4 inch blade. That's a little long for a vertical hip pocket (wallet) carry, though a diagonal rig of some sort might work.