Your XO has three USB ports that can be used to connect an external mouse, keyboard, storage devices, and possibly other hardware additions with appropriate support.
Connecting to the Internet without wireless access
You can use a USB to Ethernet connector for a wired connection to the Internet. Examples of products that work include the Linksys USB100M and the Zoltan Tech USB2.0 Fast Ethernet adapter, which cost about USD -. For a current list of USB Ethernet devices go to http://wiki.laptop.org/go/USB_ethernet_adaptors.