I got lucky one day and happened to wander into a shop that was going out of business. A lot of the tools I needed were already gone, but one of these and a graduated seat-post sizer post were still up for grabs - so I grabbed them.

I got a pretty good pile o's stuff that day, but those two items were among the great scores - even though I hardly ever use them.

For vintage stuff, almost all you need are the two Suntour ones, the Shimano one, and maybe the Regina/Falcon ones. Anything else is scarce enough to just bring to the LBS once in a while - along with a six-pack.

For the modern stuff, it's easy - Campy, Shimano, and a chain whip covers everything.