Conclusion

Globus toolkit is a long way from power grid analogy. Not surprising since automatic parallelization is unsolved problem.
Mostly a collection of services: aggregation of existing technologies with some extra glue.
New Open Grid Services Architecture (OGSA) hopes to snarf in more Web Services (SOAP, UDDI, WSDL) technologies.
Joining a Grid requires personal invitation.
Simple API is possible, but Grid rejects it because of need to support legacy software. The Grid could be very simple if we could design it from scratch!
Hard to set up, according to Kirk.