We recently reviewed the Nyko Kama Wireless Nunchuk for the Nintendo Wii, and while we considered it to be a luxury item, we thought it was a great way to rid yourself of that last wire from your Wii experience.
Now from Engadget comes word of a new wireless solution to the original nunchuk, but instead of offering a self-contained wireless unit, this adapter takes your current nunchuk and turns it into a wireless one. Just like the Nyko, this uses two AAA batteries and operates on a 2.4GHz transmitter.
From the pictures on the product page, it doesn't look like this contraption could be as comfortable as the Kama, but it does cost $15 less. However, with the Nyko you are getting an additional nunchuk as opposed to this adapter that simply adds on to one you already have. Also, the receiving adapter that you'll plug into your Wii remote looks a lot bigger than the tiny one that Nyko requires.
Product page: Wii Wireless Adapter for Wii Nunchuk Controller from Brando Workshop.