So tag clouds aka weighted list (http://en.wikipedia.org/wiki/Tag_cloud) seem to be pretty popular and gaining more usage as they seem to be associated with Web 2.0 companies. I see the pros of having them i.e. allowing users to see what the hot topic is within a site and a quick way to search. I also see the cons depending on where they are used the context of what these tags mean may be ambiguous, the time span that these tags were used is also unknown by your typical tag cloud, and the term tag may not mean anything at all to users right away. Now I've read a lot of blogs/articles with opinions on why tag clouds are good or bad, but I haven't really seen any studies to back these opinions up. Has anyone done or read any studies relating to the usability of tag clouds? Any and all information would be greatly appreciated and I'll summarise the feedback I get to this question and send it to the list.