Here is the official Cisco corporate Twitter list. OK, have to warn you ... it was posted by a Cisco public relations professional, so we can't guarantee that all these tweeps are real people and won't be sending you marketing messages. But for Cisco customers in the the Twitter world, it is a nice place to start.
Should also mention that Cisco Subnet bloggers want to be your tweeps, too.
Follow Cisco Subnet http://twitter.com/Ciscosubnet
Follow Blogger Brad Reese http://twitter.com/BradReese
Follow blogger Michael Morris http://twitter.com/mjmorris
Follow Network World http://twitter.com/networkworld
The Cisco Subnet blog is written by Network World managing editor Jim Duffy Visit the Cisco Subnet home page daily and while you are there, subscribe to the Cisco Alert e-mail newsletter, which includes news and views generated by the Cisco Subnet community as well as Cisco-related stories on Network World and elsewhere on the Web.
Follow Jim Duffy on Twitter