All of these panels are very flat with a polymer coating (instead of glass) so they can be stepped on (I don't recommend that). They are semi-rigid like the Sunware panels DDW is referring to, and probably cheaper. I have owned a total of 10 Sunware panels (not all at the same time) since 2001, and within 5 years the failure rate was 90% (only one lasted longer -- it lasted 8 years then it failed too).

http://www.defender.com/product.jsp?path=-1|328|49497|1471367&id=600715

http://www.defender.com/product.jsp?path=-1|328|49497|1485045&id=1576693

The Ganz look like the same panels I bought from http://onboardpv.com/solar_panels.php 4 years ago, but onboard PV has since raised prices considerably. I have 8 of these (plus a spare in my basement) and have been using for 3 years with zero failures so-far (knock wood). These get repeatedly soaked underway with green water where they're mounted, too.