I'm going to briefly review this ~$30 module for anyone interested in this or other options. I used the microphone supplied with the device, so no doubt it would be better with a higher quality mic.

(Pretty poor soldering job on the IC, a few solder bridges. Luckily many of the pins aren't connected to anything!)

Pros: This was easy to use and get started quickly. There was good documentation, with 15 slots for commands. The design of the commands make it easy to integrate with a project and control adding/deleting commands.

Cons: The length of command was limited to about 1-1.5 seconds, so you are limited to very short phrases. In fact, my command for turning the light on was cut a bit short, so the phrase "you must construct additional" all that was needed to turn it on (so I put a short delay before turning the light on to make it seem like the entire phrase did it, shhhh).

It doesn't seem sophisticated enough to pick keywords out of sentences either. For example, I made the keyword to be "pylons", and when I said the line "you must construct additional pylons", the module would not pick up on the word. The module would be looking for the silence before the word as it begins recording as soon as you are prompted to start speaking.

In summary, this is a good little module for a decent price if you are looking to control things with simple and short commands. If you're looking for long commands with sophisticated recognition, this isn't the device for you (which isn't a surprise given the price-point).