How to remove 3.5 mm plug tip snapped off inside socket?

[slark]

I have managed to snap the tip (see 3 on http://en.wikipedia.org/wiki/Image:Jack_plug.png ) off a 3.5 mm plug inside the audio out socket on my MacBook. I have also managed to do the same to the on-board audio out on the motherboard on a client's desktop PC . Does anyone have any ideas as to how to get one or both of the little buggers out?