SharePort also allows (trusted) friends on my network to fire off files to a printer connected to my router via USB. The beauty of SharePort is that it knows when a print job is finished and automatically disconnects users from the USB-attached printer.
The pins on the Arduino can be configured as either inputs or outputs. This document explains the functioning of the pins in those modes. While the title of this document refers to digital pins, it is important to note that vast majority of Arduino (Atmega) analog pins, may be configured, and used, in exactly the same manner as digital pins.
1 WiFly Shield - SparkFunâs WiFi Shield mainstay, this shield equips your Arduino with the ability to connect to 802.11b/g wireless networks. Then it can act as either a web server, client, or both.  Arduino Wi-Fi Shield - This is the Arduino Ethernet Shield sans wires.