Draw Something, OMGPOP's social gaming phenomenon, has already gotten 20 million downloads in five weeks and taken the top spot on Facebook Connect, and now it may have unseated the Angry Birds franchise to become the top iPhone app. Last week, the app was first on the free charts for both iPhone and iPad, but it was still behind Angry Birds Space in paid ones. When we check the iTunes store now, however, Draw Something is listed as the top-selling paid app for iPhone.

The latest numbers show that Draw Something is still gaining users at a steady clip, so it may not be long before we see it topping the iPad charts as well. For what it's worth, you'll have to go to iTunes to check these numbers — the charts shown on the web don't seem to match up at all to what's selling, not even placing Angry Birds Space in the top 100. Regardless, we imagine Zynga is feeling pretty good about that $180 million acquisition.