I recently became a member of Entrecard. I love this small yet powerful little widget! The very easy to use Entrecard program is one of the best website promtion and blog promotion tools that I have ever come across(and I have used quite a few). I am having a blast!
You open up your entrecard dashboard page, visit a few sites and click on their widget, which drops your card on their widget. Now the site owner can see on their EC dashboard that you have visited and they can reciprocate if they would like to do so.
You gain EC credits for each operation that you perform(dropping your card on people's widgets, visits to your site, etc). You can then exchange these credits for ads on other blogs. Although I've just started using EC, I can already see a sizeable increase in traffic on all three of my blogs.
Other blogs use their credits to advertise on your site as well and the ads remain for one day and then the next queued ad is shown.
These are my cards:
If you aren't using EC right now, you are missing out on some quality traffic and some amazing blogs!
Check it out!