I wanted to use a DHT22 to measure temperature and humidity, and the only library I could find was the one from Adafruit. Unfortunately this library blocks execution for about 300 ms, which is not acceptable for my application.
So, I whipped together a library based on Adafruit's code that reads the temperature and the humidity from a DHT11, DHT21, or DHT22 sensor without blocking execution, except during the actual data acquisition which is timing critical.
Thanks. I actually discovered this library myself shortly after writing my previous post. It probably wouldn't be ideal for my application, though, because I'm using a somewhat aggressive timer interrupt to control a stepper motor. I'd have to share the interrupts then.