I am working on an a Raspberry Pi based, Internet connected indoor air quality monitor called LiV Pi. LiV is an open source hardware and software project. LiV measures temperature, humidity, air pressure and CO2 levels. I wanted to be able to write measurements data from Raspberry Pi into Xively, an IoT platform. Please refer to gitHub link for a code sample. You will need to register with Xively and create an account.