I'm getting a MBP 13 in a few days and I noticed on my brother's theres only one audio socket for in AND out, but not at the same time. I use garageband quite a bit and I might get logic 9 soon. I play my guitar into garageband but I clearly cant do this on the MBP like I could with my old macbook. What's the best way round this? I don't want to spend loads of money and I'm not a professional recording artist or anything it's just a pass time for me. Any help or advice would be much appreciated.