SchoolSurf.org is a web proxy. Just opened in late August. It has a nice, easy navigation. Over 170k hits as of 9/11/2007. Have 3 options:
$5 a month - Image banner. Standard size. Currently no other banners in rotation

$2 a month - Text link of 3 or less words on www.schoolsurf.org

$1 a month - Text link on partners page.