Check out this video showing that you can download iPhone applications from the internet and drag them into iTunes. iTunes recognizes the application as an iPhone application and places it in "Applications" in iTunes.
The user downloaded an application called "Neverball" from a webpage then dragged it into iTunes. It is not yet known if you will be able to sync these applications to your iPhone or iPod touch. The fact that you are able to do this in the first place looks promising.
***Disclaimer*** I did not make the above video.
Labels: iphone 3G