In order to make your ipod wireless the simplest way is to first make it Bluetooth-enabled.
How? Simply by connecting a Bluetooth transmitter
You have 2 choices. You can use a:
1- Bluetooth transmitter specially designed for iPods with a dock connector
2- Universal Bluetooth transmitter that will connect via the 3.5mm audio jack (wired heasets output)

Which one should I choose?

a) If you want to play music from your iPod and only your ipod, pick up one in the first category since the transmitter is bound to the iPod without cable. Some are a bundled with a pair of Bluetooth stereo headphones which will save you some money.

Otherwise pick up a transmitter and select the Bluetooth stereo headphones of your choice. You can substitute the stereo headphones with a Bluetooth speaker (or get both!) to share your music or throw a party in no time.

b) If you are planning on playing music or sound from your iPod but also other audio sources it is wise to go for a universal Bluetooth transmitter. You can pick up a transmitter by itself, and select a Bluetooth stereo headphones or speakers, or take advantage of the fact that several stereo headphones come with a Bluetooth transmitter. Now you can play music from any MP3, CD, DVD players, PC, Laptop, TV, Boom Box, etc.., to Bluetooth stereo headphones or speakers.

Remember that most of the Bluetooth stereo headphones have hands-free capabilities, allowing you to switch between music and phone calls (from a paired Bluetooth cell phone).