AKCP makes an airflow module for their network-connected SensorProbe. Might be what you're looking for. I've been satisfied using the SensorProbe for monitoring various conditions around the data center for years, but I've never used the airflow module.
http://www.akcp.com/products/intelli...ow-Sensor.html
A company called avtech also shows two airflow sensors on their site (avtech.com/products/), but I don't have any first-hand experience with that company.
Ken