Multiflex3 is a fixed width, neutral green and grey business style layout originally created by Gerhard Wolfgang. It can be found at http://www.openwebdesign.org/userinfo.phtml?user=gwolfgang
There are a lot of options that you can browse in the "multiflex3/multiflex32_original" folder that take advantage of different block colors and other effects. I included all of the original CSS so you should be able to plug-n-play new class properties in the .thtml files if you so desire. Also, I included a collection of public domain country flags for use in the top header. To use them, simply unzip the ones you want and upload them to "multiflex3/images" folder and make the appropriate change in header.thtml.
Finally, this theme supports the Forum plugin v2.7, with its layout options in "multiflex3/functions.php" with some navbar layout enhancements that didn't make it into Blaine's final 2.7 release, but which will be incorporated in future updates.
I have tested it in Firefox2, IE 7, Safari public beta 3, and Opera. In other browsers, your mileage may vary.
Download it here.