To see this project in action - Follow this link
I am a big fan of Xively (before that Cosm). I have blogged about in several occasions.
Unfortunately when they switched their name and went from Cosm to Xively, they forgot something extremely important for me: the ability to see more than the last six hours of data. Thankfully they have a great JS API and I built this simple viewer to watch how my data evolved over time.
This project is released under the MIT open-source license.
Lots of credits go to Jason Neylon who had the same problem and found most of what was needed to make this happen. I have just made it more generic.