you can use the links preview macro to get previews on google search and on all other sites as well
you can download the macro from there:
http://kmeleon.swiftfree.net/macros/linkpreview.kmm
aftersaving in kmeleon macros, restart kmeleon and right click on a page and select activate previews.
i think it can be made to work automatically with onload instead on oninit and restrict it to google domains only.. but check it out first and see if you like it.