Grid technologies have been a side interest of mine for some time. I am not actively involved in any projects, but really enjoy reading about what people are doing with it and the potential it has. I have a product offering in my head wrapped around the DataSynapse products, but just can't get it on to paper. DataSynapse makes very cool software and seems to have a very balanced suite of applications.
While surfing around today I ran across this article at WHIR. It is worth a read as it explains how hosting companies are starting to utilize grid technology. It also has several good links to technologies and companies.