0-> If u just want to "record songs people sing" , you could better go with a mp3 recorder , it would be about 1k for 2gb!! {more less in national market} , u can directly connect the mic's o/p to it and record :) adding more , if u are looking for a video recording interface for your lapi , you can go for Sony it's would cost you more {check out ebay to just see how it looks}
mp3 is patented I wouldn't want to use it. Is there something which
will record ogg or a non encumbered format