I think what you are trying to do here is JMS Request/Reply. Have a look at http://fusesource.com/docs/broker/5.5/explore_jms/ExploreJMSReqReply.html as it will allow you to send a request and wait for a synchronous response.
If you need to aggregate several responses before send the message back to the producer then have a look at FUSE Mediation Router (based on Apache Camel) and its Aggregator component ( http://fusesource.com/docs/router/2.8/eip/MsgRout-Aggregator.html )
Hope this helps,
Hi, thanks for the reply.
What i'm trying to develop is a scenario similar to the 'Who whantst to be a millionaire' and publish questions that clients can reply using publish-subscribe.
I don't think Request and Reply is suitable.
Perhaps, both sides, server and client acting as producer/consumer?