make use of a harddrive and support FAT16 -> 3 Gigabyte.

Store all data on the harddrive in binary format. Next: copy all data to a PC and process your data.

USE in any search engine :

MP3 player

This gives you many application notes on how to interface a harddrive to a microcontroller.
FAT16 can be found under 'freedos'. Lot's of open C source.

Have fun