This native application sets up an AFP file server on your iPhone or iPod Touch and also provides a simple GUI interface for controlling the file server.

Changes:

Compatible with 1.1.3 firmware.
Uses -w flag in lanchctl for afpd.
Go button auto enables/disables as user types.
Share names have new defaults.
Added default share for ~mobile.
/Applications/AFPd.app/afpdcontrol must be 4755 mode.
Error is shown if permissions are set wrong.

http://www.eecs.berkeley.edu/~job/afpd/AFP_File_Server_on_your_iPhone.html