It is not possible to host more than one top level site via MobileMe. By "top level" I mean you can't have [/URL]www.domain1.com and [/URL]www.domain2.com[/URL] on the same account. (please excuse the "url" tags. The board system wants to turn the example domains into links, so I put the tag in front to cancel it out)
In order to host more than one site on an account you may be able to put sites into sub folders, so then your web addresses would be [/URL]www.domain1.com[/URL] and[/URL]www.domain1.com/domain2[/URL], but that is really not two separate sites.
However, you can host more than one site with most hosting companies, and with iWeb '09 you can upload (publish) using standard FTP. I believe the only things that do not work with publishing to another host (other than MobileMe) are blog comments and picture slide shows.
We have a basic webhosting package called the "
Small" which allows you to host 2 top level sites, has actual @yourdomain.com email addresses. This is similar to other options at other companies (except we are Mac centric). MobileMe is expensive if you are looking for web hosting and email, and most of the cloud computing options MobileMe offers can be done free through Google.