One of the biggest issues I had with the Wii was the Nunchuck. It felt bolted onto the the console and was basically a way to add a few triggers and an analog stick to the Wiimote. Not amazing and, when in the heat of battle, prone to flinging out of your hand and flailing wildly.
Nyko took a look at the Nunchuck, said we can make this better, and has with their $34.99 wireless solution.
The Kama uses an unpowered transmitter and a powered receiver. The transmitter fits on the end of your Wiimote, adding about an inch to its length, and the receiver looks like a Nunchuck without the cable. You drop in two AAA batteries, pair the device by hitting a small, blinking button, and start playing.
The Kama is a little light and, without the cable, feels insubstatial. However, it includes a wrist strap to keep you from dropping the thing and you get a considerably larger range of motion by knowing that you can move your arms in almost any direction and still have it register on the Wii.
If you play Wii, get the Kama. It’s adds a level of freedom not found in the wired version and ensures you won’t start flailing your controller around like a madman with a slip of the wrist. For a little less than a Wiimote, you get a bit more usability.