Custom tag cloud.

Not sure exactly how to describe this, feel free to ask if you have questions! I want a block on my web page, maybe a table or a css block. ? I may do this in many sizes so it has to be configurable. I'd then like to display many works different positions and colors, like the tag clouds you see all over. I also want it so that the words in the clouds will be seen in the source. So search engines, adwords, etc. can grab them. Tell me your thoughts on how to make this happen and bid if you are clear. Thanks!