UPDATE, don’t use Entrecard, they are backstabbing type of people.
Entrecard and Blogrush both have customer service problems. Blogrush died already and Entrecard will too soon. 🙂
Lately, I’ve been keeping a keen eye on my friend Graham Langdon, creator of Million Dollar Wiki. He has created a new site called EntreCard that allows bloggers to advertise for free on other blogger’s blogs. Basically, bloggers can trade 125×125 pixel ad spots.