The highly versatile TinaPOS, now Openbravo POS can be populated easily with list of Products, its prices, and even its On Hand Qty for different locations. And it can be synched to any remote location in the world. We tested this well in the Open Source Lab at the Asia Pacific College, Makati, talking to the ActiveMQ server in Munich. Testing done with 5 separate POS stations concurrently. Detail log notes here but you ought to see a movie of it too.
There is a detailed PDF Guide together with all the rest of the codes here.
After the daily sales are made, the POS stations can synch back to the remote ERP server again via ActiveMQ and the ERP then import the orders to get a virtual but accurate view of the different store dispensed quantities. The activeMQ flavour used is Stomp. It can be set to persistence mode as you can see the real server in use in Munich at: http://jenkins.idempiere.com
This integration might be of great interest to the community particularly that Openbravo is showing signs of 'fee' tendency:
12 December 2012 Note: With the introduction of iDempiere, this has become a plugin and deploy-able remotely without a pit-stop! See movie below.