Related to Vitaliy's question about if these other Moon's orbits can block the Sun, this link seems relevant. In all cases, it appears that yes it's possible, but depending on the orbital plane of the moon with respect to the orbit of the planet around the Sun (the ecliptic), this may happen more or less frequently. Most of Jupiter's moons have orbital planes that are almost the same as the ecliptic, so eclipses are frequent (at least one per orbit of the moon). As the planet's axis tilts more, the orbital plane of its moon's also changes so you end up with 2 points along the moon's orbit where it intersects the ecliptic. If the moon happens to be at one of those points when the Sun is also there, you get an eclipse. This obviously happens far less frequently.