Create the website in iWeb, then highlight the top-level site in the left-hand sidebar (usually the title of your site).
Then, under "Publishing" in the main window pane, select one of the following:
- MobileMe: for publishing to MobileMe
- FTP Server: to publish remotely to an FTP server
- Local Folder: to save the web site/structure to a local folder, so you can manually upload it to the place of your choice
I think he's talking about that widget that says MobileMe Gallery, which I guess you could call "Sexy." I'm pretty sure that, that is one of the bunch of things that require MobileMe.