My sister has been wanting an mp3 player recently, and I found an RCA Opal on sale for her. Additionally, I found that this mp3 player has the option for line-in recording, which might come in handy for me to borrow it for a few concerts I will be attending this summer. So I have researched and know that the norm is is to use the mic-in input found on some MD Players and DAT recorders and the such, but I want to know: Is it possible through some kind of microphone setup to amplify the microphone so that it would be able to record a concert decently through a line-in port? I am not looking to need any supreme level of quality from the recordings, just an enjoyable amount of quality. Any recommendations for microphones/battery boxes/amplifiers or anything of the sort to make this work would be greatly appreciated. Thanks.