Bill,
EJB's are single threaded, hence only one method invocation can be executed on an EJB at a time. Therefore, as previously mentioned the Container can spawn multiple instances of stateless session beans to handle multiple client invocations.
The term stateless simply means theres no affinity between method invocations from a client to stateless sb. But, just like any
java object its can have state, but its not associated to any single client.
hope this helps.
Rowan