So I just found out about XSpaces reading Jon Udell's blog.  XSpaces are free, public key-value pair stores that you read and write using SOAP.  Pretty cool.  They could be used as publically acccessible blackboards (remember blackboard architectures from your AI class?) for sharing information between programs.  Kind of like Internet dead drops. 

The next logical question, at least to me, is: if a SOAP accessible hash table is a good idea, why not other data structures as well?  Could we use a similar stack space, queue space, etc.?  If not, why?  The second question I have is: now that we have reinvented shared memory on an Internet scale, shouldn't we have a companion semaphore service?