Enter SupportDetails.com which captures all the vital stats about operating system, browser version, screen size, cookies, flash version and more. Not only this, all they need to do is enter their email address and this information reaches you. Nice!
Thanks to Tom Bamford for the tip here
Recently Bitly published a blog post reporting evidence which concluded the average half life of a Tweet was 2.8 hours. This highlights the importance of considering when you post, the achieve maximum effect. It is best to publish when the largest portion of your audience is online and primed to listen.
Fortunately Bitly also published some visualisations which illustrate over a week which times are the most effective to post and get viral effect on Facebook and Twitter. These two reports combined should help to guide and inform you as to broadly when is best to Tweet and post Facebook updates.
However, you must always consider your audience and their habits. These statistics are for USA and across all sectors. They are starting point. Ensure you always use measuement tools, like Bit.ly stats to indetify when your specific targets are active, to refine your social campaigns accordingly.