It's got everyone excited, but just how entrepreneurs can participate today is not immediately clear. There are a lot of folks reading through arcane distributed processing literature out here in Silicon Valley, scratching their heads.
A good place to start watching the Grid is the Globus Project, initiated by Ian Foster and Carl Kesselman in 1999 as a blueprint for a new computing infrastructure to enable scaleable virtual organizations. As you'll see, Globus is an open-source toolkit for enabling computers and applications to be participants in a grid system.
Grids, according to the Globus Project, are "persistent environments that enable software applications to integrate instruments, displays, computational and information resources that are managed by diverse organizations in widespread locations."
Today, the focus is primarily on software, a middleware that provides the glue between users and distributed resources out in the network. That middleware needs its own set of protocols, its own method of ensuring security and distributed resource management. It will rely on the development of APIs (application program interfaces) and on a wicked fast, data-optimized network infrastructure. Globus is also developing applications that are purpose-built for grid computing and has released a couple of versions of its toolkit for developers.
Also take a look at the Global Grid Forum, which is going about developing the concepts of an Integrated Grid Architecture that will facilitate the development of grids, large and small, around the world.