I surfed around and found something on

[url]http://www.casestudio.com[/url]

Its pretty good, you can draw er diagrams, generate sql scripts from it, but it does not have all the sophisticated features of ERWIN like reverse engg etc.

Bad thing is the eval copy supports only 6 tables, so we are forced to buy it from them, but the good thing is it only costs around 150$ for single user license whereas ERWIN costs 4000$ for a single user license