For can opener, scissors and needle-nose pliers, the only real option is a leatherman or one of the many similar tools. However they tend to be a fair bit of weight for things that are "just in case" tools.
Sometimes I take a Leatherman Juice CS4
, which is small and fits the bill, but more usually I forego the pliers and just use a Victorinox Climber SAK, which has better can opener and scissors.
One thing to note is that Leatherman-alike tools are usually poor at cutting brake/gear cable. The hinge isn't stiff enough to stop some strands doing a zig-zag between the jaws of the plier, which then jams in the shut position as any attempt to open the jaws just folds the handles. I've tried (or watched the attempt) 3 models of genuine Leatherman, a Gerber Legend, and a couple of cheapo copies, and all have had a similar problem with stranded cable.