Guitar into Macbook Pro - help!

I recently got a macbook pro 13 inch, and as many of you are probably aware, it doesn't have a audio line in jack! Im talking about the 1/8 inch one thats usually beside the audio output hole.

I used to plug my guitar straight into the computer using a normal 1/4 inch ended chord with an adaptor to make one end 1/8. Although I just recorded with garage band, i actually didn't mind the sound at all.

I don't have a mixer that connects to usb. Nor do i have earphones or head phones that are usb ended.

Ive read a little about how the audio line out is also a line in, and you need to change system preferences or something to change it.

Does anyone have any advice or recommendations on what to get so I can start recording again? Cheapest mixers that have a usb line are around 100 dollars at the music store. I went to some electronic shops and they didn't have any cheap mixers. They seem to have head phones and earphones with usb lines though.

I don't have that much money, and Im wondering if making the audio output into input and then using usb headphones would be the cheapest way to do this?

Any advice or information on solving this problem would be much appreciated.

Thanks!

I'm going to bump this thread. I think i am asking a clear question.

thanks

I don't have the 13 inch so i don't really know how to help you on that.I can recommend an interface, which i know you are short on funds but it's the only way i know to get you up and running PreSonus AudioBox USB 2X2 USB Recording System Standard and more Audio Interfaces at GuitarCenter.com.

There are others too. You plug this one into your usb and your headphones plug into the audiobox . Works great