need audio recorder for my cell

I am having nokia n73 & i want to audio record some of my lectures & listen to it later?
as i am attending some lectures & forget some of the points by the time i reach home,for that reason i need a audio recording software for my mobile which can record upto unlimited time & even if there is any software thru which i can upload on my desktop & save them forever on my system.i am having nokia n73