How much mass does the W boson have?

And why it matters

Whenever I describe the fundamental forces to an audience that does not entirely consist of other particle physicists (happens more often that you might think), it is the weak force that causes trouble.

Electromagnetism holds atoms together (amongst other fun stuff), the strong force holds atomic nuclei together, and gravity holds the planet together. But what does the weak force do? I am usually reduced to hand-waving about neutrinos and the Sun, in a faintly unconvincing fashion.