Citrix has an opening for a Xen Evangelist. From their blog:

"The Xen Open Source Evangelist will be an advocate for projects (Xen, Xen Cloud Platform and Xen ARM) and be primarily engaged with open source Xen users, upstream and downstream projects of Xen as well as developers of projects. In addition the Open Source Xen Evangelist will be responsible for representing Citrix and explaining their products and services in the appropriate venues."

It goes on to say that the person would demo and speak at key events around the world, communicate with the community, educate people on Xen and encourage the community to contribute to Xen.  
Sounds like an interesting opportunity. For more information apply at the Citrix site