Curtis mp100 mp3 player mod ideas

Hi all,

It my first time posting and I wanted to get some ideas, I found a old mp3 player of mine its a curtis mp1000 1gb mp3 player, its a self contained usb rive and uses a aaa battery for power. I am looking to make it a bit more useful to myself, I wanted to know if anyone would have a suggestion as to how I can make this into a good voice recorder, it has a mic already. I plan on using it for lectures ect. I was hoping that I could add a rechargeable battery that recharges off the usb connection, and somehow expand the memory while leaving the buttons and their controls intact.

This may be impossible, but let me know, and thanks in advance for whatever help I receive.