Here are the first results of our search for a decent hosting provider that allows MonoX users to install and use the package without problems.
We are reviewing more than 20 hosting companies.
In the "classic shared hosting", we can confirm that MonoX works out of the box with DiscountASP.NET. It is a low-cost option ($10 monthly for Web hosting + $10 for SQL Server 2008 hosting) and it works on default settings without any problems.
A more expensive, but much more powerful option is offered by VPS and cloud based services. We can recommend both Softsys hosting ($37 per month for the smallest Windows plan) and Rackspace (approx. $60 for the smallest Windows plan). You get remote desktop access and full control of your virtual server, which makes all installation and maintenance tasks very easy. We have test instances of MonoX running on both services, and we will report results of a load testing sessions soon.

Another hosting company that should be mentioned here is Arvixe, you will get MonoX preinstalled with unlimited disk space and database accounts for just $5 per month.