Skype doesn't currently include an answering service, so somebody else has created one for it.

SAM works just like any standard answering service. You simply record your greeting and then, when activated, SAM will intercept incoming calls, play a greeting and then record the callers message.

You can configure various settings, including the number of rings before SAM answers and the maximum length of message that can be recorded. You can also have different greetings/settings for Buddy and non-buddy calls.

We have read reports in the blogging world of a small bug, where if you are on a call whilst somebody else leaves a message the caller on the line can hear the message being recorded. We were unable to emulate this however.