Hi everyone, I recently got a 2011 13'' MBP, and found out one problem that I am not sure how to solve. Thing is - I play a little slide guitar. I am not a pro, so I don't want to spend money on amps and pedals. So I was playing through Garageband on my mac pro (desktop mac). What I did - I plugged my guitar via jack-to-minijack connector into Line In port of mac pro, and was playing through garageband, listening to myself through headphones or speakers. Today I wanted to play with the band, so I just grabbed all the wires, MBP and guitar to the practice, and found out, that my MBP has no Line In port. So i could not play at all, because I found no way to connect my guitar to MBP. When I got home I googled, and found this article http://www.pocket-lint.com/review/5295/apple-macbook-pro-2011-review that says, that 13'' MBP has line in and out combined in one port. I know I might simply buy external audio interface, but I'm not a pro, so I don't want to spend a lot of extra money on it. So my question is: is there any way to play guitar through built-in hardware of my MBP? I need both, line IN and OUT working at the same time. Is that possible? I've seen some splitters, 2 'mom' jacks that are combined into one 'dad' minijack. They are probably used to make 2 mono channels go into one stereo channel. If that 3.5mm port on my MBP could both take and give away signal in the same time, in theory such splitter might work. But I am not sure at all, so I need some advice from you, guys. Thanx!