Product review (4 stars): Great sensor; used it on SparkCore
This was very easy to use and set up. I actually use it with a SparkCore and I loved how easy it was to get this set-up with Adafruit's Arduino library. Also their tutorial really helped: https://learn.adafruit.com/dht

It *is* pretty slow... it only takes about 250 milliseconds to actually read from it, but readings can be a few seconds late. Also if you move the sensor to a different environment (for example, inside to outside) it could take a while before it reflects the difference- like a minute or two- if it wasn't for that, I would have rated it 5 stars.

Keep in mind you're paying extra for the nice little package with the resistor. If you wire it yourself (just need a resistor as shown in the Adafruit tutorial) it's like $5 for the sensor. (And a few cents for the resistor)

Please note that there is a more accurate version of this sensor over a wider range: the DHT22. You can even use the same Arduino library for it. If I would have known that I probably would have bought that one instead- however, for what it's intended for, this sensor is great. I still haven't tried the DHT22- I'll have to write about the differences between the two when I do. I'll be using these sensors to build a device for my brother to help him monitor humidity in his basement.