Do you have a favicon on your site? Years ago, we encouraged everyone to make sure their website designer included one, but the trend rather fell off, as despite being shown in bookmarks or favourites, and in the browser location bar, there seemed little other purpose. And designing a meaningful favicon at 16 x 16 pixels takes some skill!
However, it seems that favicons are back in favour. Yahoo are testing favicons in the Pay Per Click results, displaying a favicon from the site as an additional mechanism to help users recognise known brands or to help expose lesser known brands in extra ways.