Now that tagging is all the rage, tag clouds, weighted lists of tags, are becoming a more frequently encountered user interface device. For a weblog visualization project I'm working on, I pondered for a half a second using tag clouds liberally, but didn't have time to think through the details.
Fortunately, Joe Lamantia did have the time. In a two part series, he delves into the semantic underpinnings of tag clouds, and future directions for the design and application of tag clouds. There's a little too much background material for me, since I'm steeped in the stuff, but the thinking is definitely going down an interesting avenue. The main point is that variations of tag clouds will start to exhibit more interface elements to understand the context in which the cloud was generated, or even interactively control the cloud contents. I especially like consideration of incorporating temporal dynamics into tag clouds, a.l.a Oliver Steele's Expialidocio.us.
Updated to correct the outbound links.