pt in sd -

If your Mac has an external mike that you can unplug, unplug it and take it with you to Radio Shack (so you can match it up - it could be a mini or micro plug - or some stange Macish thing). You should be able to find a conversion plug that takes the 1/4 plug on one end has has a plug to match your input hole on the other for well under $20.

I'd guess a straight plug would be more like $6 or so, but you might want to look for one with a short "pigtail" so your mini jack socket doesn't have to hold up the adapter, since it will be a little bigger than what you normally plug in there.

If you don't have a Radio Shack handy - any decent audio shop.

John