This morning I came across this picture of a multi-purpose Roman dining tool (200–300 AD; via Make via Neatorama via The Fitzwilliam museum):

I doubt I've ever had anything so handy in my picnic basket. But this reminded me of a nagging dilemma: where is that perfect, do-it-all multi-tool for bikes? Considering how far bicycle design has come, how many different disciplines there are, how many cyclists are out there riding right now, I'd think that the problem of the multi tool would have a better solution by now. I've owned several, used several more, and browsed through hundreds looking for the best one. And while I know that "perfect" will be different for different folks, I'd like to ask you: what's the best multi-tool out there, and which features make it so?