force.com Schema Utils for Chrome
More About force.com Schema Utils
2. Extension provides Export Diagram button in maximized view which allow users to download schema diagram in PNG file.
1.Please rename downloaded file with PNG extension.
2.Performance of this extension is not tested, It may not work properly on low end machines.
// author: Ajay Singh Hada: http://facebook.com/ajay.hada || http://in.linkedin.com/pub/ajay-hada/10/3a7/379