There are many protocols available to get data from a networked Arduino or compatible board, and one of these is MQTT - "MQTT is a machine-to-machine (M2M)/"Internet of Things" connectivity protocol. It was designed as an extremely lightweight publish/subscribe messaging transport" (mqtt.org).
Thanks to the low bandwidth requirements MQTT works well with our Arduino-compatible equipment and a neat example of this has been demonstrated by Marek Kuziel whose weather station returns temperature, humidity and other data via MQTT. Marek's system is self-contained thanks to the use of our Freetronics EtherMega and the extra Power-over-Ethernet adaptor, which allows the hardware to be powered over the network cable - so a power supply isn't required on site.
Furthermore with Marek's example sketch you can see how to send data as MQTT messages which can then be subscribed to via a remote server, Android device and more. To get started, visit Marek's interesting website. And for more, we're on facebook, twitter and Google+, so follow us for news and product updates as well.
If you're interested in using an Arduino Mega with Ethernet, a microSD card and more - it's time to upgrade to the Freetronics EtherMega:
Quite simple the EtherMega is the fully-loaded Arduino-compatible board on the market today. Apart from being completely Arduino Mega2560-compatible, it includes full Ethernet interface, a microSD card socket, full USB interface, optional Power-over-Ethernet support and still has a circuit prototyping area with extra I2C interface pins. So if your project is breaking the limits, upgrade to the EtherMega today.