I just set up a newly purchased TwitterScreen, the elegant application from Koz Farina that allows you to have a device in Second Life that dynamically reads/loads messages from a twitter account so they can be seen in Second Life.
The screen works great, but even better, it comes with a TwitterHud, a device that allows you to send a tweet from within SL via the chat line.
The tweet I am seeing here in Second Life was one I sent from Second Life.
The location is my own new little bit of SL land. I have a lot of building/learning to do when I get home!