Headphone/microphone

I have a G4 powerbook, 1.33 15 inch which has an audio line in port and a headphone port.

I have a logitech headset with microphone where I cannot get the mic to work as I am assuming the powerbook has no mic port.

So is it a case of getting a USB headset or is there any adapter I can use? I need it for Skype, I have tried internal microphone but there is too much feedback at the other end when talking.

It is okay, I need a powered mic or the imic apparently. TBH I think that is really bad considering the price of a powerbook

I have just spent £30 on Logitech mic and headphones for Skype - now I have to spend more money to get the mic to work - I feel cheated.

http://docs.info.apple.com/article.html?artnum=86771