If you are using Entrecard you possibly also heard of Entrebar a plugin for Firefox 3.0. I was a bit sceptical about this but I thought give it a try and I most say it works really great for me:

• I try to re-visit all Entrecard droppers, but the Entrecard website I always lost track where I have been. 
  With Entrebar just select Inbox and click on the double-arrow and 10 websites will be opened in different tabs! The good thing is: Only those websites will be opened where you have not dropped your Entrecard yet (unless you change some settings).
• Same if you want to browse Entrecard for Most popular, Random, Cheapest, Newest, Most expensive or Most advertised blogs. Just select your category, click on the double-arrow and 10 websites open. If you click on the single arrow only one website opens.

I used this the last few days and found some really nice and interesting blogs. You can also use Entrebar to add blogs to your favorites or to place your Entrecard-Ad onto a website. Entrebar shows you the price in "ec" and because you already look at this blog you know where the Ad will be placed.

If you use Firefox 3 and Entrecard you should give it a try.