[outlet] has created a project that has it all – Netduino! ioBridge! XBee! ThingSpeak! He wanted to use the ioBridge IO-204 as a serial gateway for XBee (ZigBee) wireless sensors connected to ThingSpeak. The XBee radios are attached to a pair of Netduinos that send the data serial data via the IO-204 to the ioBridge Serial Web Services API. At this point, ioBridge relays the data to ThingSpeak, but could send the data to any website.
Outlet has created a detailed Instructables to guide you on how he created the project. This project is at prototype level, but we could see how this could be packaged into an efficient setup and used for many applications that require wireless sensors and remote monitoring and reporting. This is on the same lines as the ioBridge Tide Alerts product used by many marinas to measure and alert tide levels in real-time.