A note for application developers: I find it hard to get the logo of any website due to the fact that most websites use css-sprites to show their respective site's logo. If I am having a public site and would like to give information about other sites, I am not able to show the related site's logo because the logo is embedded with other images in a css sprite. Consider, I like to show Twitter's bird logo in my pubic listing but it's infact a css sprite like this
https://g.twimg.com/sites/all/themes/gazebo/img/sprite.png In this case, there is no way to show the site's identifiable logo. I would suggest developers to have site's logo as a separate image and don't mess up with other css sprites as this will hinder from showing your identity uniquely.