Straight adapter from mic to macbook?

It seems like I remember someone telling me that it is possible to run a mic straight to your macbook via an adapter. Can anyone tell me what this is called? Where I can get one? Price?

all depends on what kind of mic you want. they make XLR to mini adapters, but ive never had good luck with them. some mics have a 1/4 stereo or mono plug. for that youd have to get a 1/4 to 1/8 adapter. ive had problems with these too, the come loose prety easily. there are also USB mics. ive actually been really surprised at the quality from these. hope this helps.

Thank you my friend, you have been most helpful.