How interesting – and obscure – but Amazon is just offering a Queue Service
You can queue up to 4,000 msgs of up to 4096 bytes during the beta period.
How will this be uses and what’s the intent? Maybe to coordinate among distrubuted and cooperating web services.
What’s interesting is Amazon is seemingly offering a generic infastructure component here. You could see Google doing the same.
Playing around with it is pretty smooth. Looks like queues and queue entries have unique IDs. When you register you’re given a unique subscriber ID and that’s how you access your queue. Attributes of a queue are name and a “read lock timeout”.
It appears there is not atomic read+dequeue operation. The read they supply is a kind of “peek” which does not alter the queue -you’re then supposed to call dequeue to remove the entry, thus mult readers may get same data ( though they do document this clearly).