Updating your status on Activator used to be only for Twitter. Not any more, "Fusion" is a new jailbreak tweak that allows you post your status to Facebook, Twitter, Foursquare and Myspace using Activator. It is a great way to connect to all social networks at once saving you some time. Get Fusion from Cydia under the BigBoss repo.
Once you get it, open up Fusion's settings and set the activation method for "compose tweet". There are some other things that you change such as the order of these sites. You can also set it for Siri. You can find the information about setting Siri in the tweaks settings.
When you are done with the settings, activate the "compose tweet" however you set it. You can type as a regular tweet. But when you click that button on next to the location button, it shows you the list of your social sites. Tap on each site you want and your post will be on all the sites you checked.