MongoDB as an MQ persistence solution

After reviewing several message queues (ZeroMQ and RabbitMQ looked fine, but ZeroMQ has no durability and is in fact more a protocol than an MQ, and RabbitMQ has that "solutionness" all around it), we decided to roll our own simple MQ, using MongoDB (multiple publishers/multiple subscribers with implicit configuration). After I completed the implementation, a reference to a nice article about MQ in MongoDB popped up on mongodb-user or mongodb-masters list, so I got assured that the idea itself was O.K. Too bad I found another article on the same topic late enough -- while I had the idea of using capped collections (and rejected it because write performance isn't that important for our MQ, while persistence is), using tailable cursors just didn't even appear in my mind, although I knew of the feature's existence. Many thanks to the author =)