I’m filing this away in the ‘finally tracked down why’ bucket. In case anyone else spends time on Pidgin wondering why some of their contacts have lots of “Status” lines, here’s the reason. In particular, I’ve noticed that when I chat to Tim using Pidgin and Google Talk (which is based on Jabber/XMPP), he has approximately 10 “Status” lines when I mouse-over the name (the number varies, but not by much). It turns out it’s a simple explanation — Google Talk allows you to log in from multiple clients on multiple devices (this is part of the XMPP protocol), and Pidgin supports that.
Hence the multiple Status lines, one for each device that’s logged in to the XMPP server. The whole thing seems to be clever about sending the messages to the appropriate device, it all somehow just works. The other systems I use to chat with people via Pidgin (AIM or Yahoo!) don’t support logging in from multiple computers (although it looks like the AIM protocol itself does, but they don’t support it with most clients).
I guess this is generally a feature, but it does mean people need to be fairly careful about figuring out which chat client they want to use when they have multiple clients on multiple devices (and since ‘clients’ includes GMail, one for each Google account, they can easily add up). Still, Pidgin/XMPP seems good at figuring out when someone really is ‘Available’ rather than ‘Away’ and routing the message to the right place so it’s probably not as much of an issue as it could be.