OverSkreen for Android is a multi-window multitasking browser
However, developer MBFG is looking to give multitasking one app at a time. The developer has already released "floating" versions of calculator and video player apps into the Market, and now it has added a floating browser, called OverSkreen, to the mix as well. This means that users can have a browser window which is not automatically full-screen, allowing you to see the homescreen, or tile browser windows side-by-side, or on top of another app.
For a limited time, OverSkreen is 50% off as a launch sale, which means you can get it for just $1.49 in the Android Market. All MBFG apps have very high ratings in the Market, so it seems like a solid app. If you need a bit more convincing, we've got a demo video for you, although it is in German.