Which of Jupiter's moons did I most likely see? I was gazing through my binoculars at Jupiter last night and noticed 3 (maybe 4) tiny dots in line with it. A first I thought they might have been background stars but quickly realised their colour was similar to that of Jupiter and their brightness was larger than expected considering their size. As a result, I'm pretty certain I was looking at Jupiter's moons.

Presumably, I was seeing the largest of its moons (Io, Europa, Ganymede, Callisto). They were far too tiny to see any details, obviously, but would it have been only those moons I could see? I assume the rest are too small. And is seeing those 4 moons as tiny bright dots through my 7x50s feasible?
The galilean moons are visible in binoculars, indeed. Yesterday evening (assuming you're in the western hemisphere), 3 of them were visible as separate dots. See the chart here:

http://www.wolframalpha.com/input/?i=jupiter+galilean+moons+on+march+6+2016+at+9pm+pst

You can adjust the query to reflect your time zone, and the actual date/time of the observation.

There are also smartphone apps that allow you to determine the position of the moons at any given time. On Android I use the Moons of Jupiter app.