Turns your phone into a mini sever that allows another device with a browser to view/dowload files on the SD card. The other device must be on the the same wi-fi network.
Access from e.g your PC is by entering http://:.
IP address and port number to use are displayed on the main app screen.
Doesn't run in the background, this may be a security feature to prevent accidentally leaving the server running.
Tested on Hero, Android OS 1.5