What can you use the iPod 4th generation bluetooth for?
The iPod touch 4th gen should allow you to do the following:

iPhone, iPad, iPod touch: Supported Bluetooth profiles


With A2DP:
This profile defines how high quality audio (stereo or mono) can be streamed from one device to another over a Bluetooth connection. For example, music can be streamed from a mobile phone, to a wireless headset, hearing aid &amp; cochlear implant streamer, or car audio or from a laptop/desktop to a wireless headset.

With AVRCP:
This profile is designed to provide a standard interface to control TVs, Hi-fi equipment, etc. to allow a single remote control (or other device) to control all of the A/V equipment to which a user has access. It may be used in concert with A2DP or VDP.

With PAN:
This profile is intended to allow the use of Bluetooth Network Encapsulation Protocol on Layer 3 protocols for transport over a Bluetooth link.

With HID:
Provides support for devices such as mice, joysticks, keyboards, as well as sometimes providing support for simple buttons and indicators on other types of devices. It is designed to provide a low latency link, with low power requirements. PlayStation 3 controllers and Wii Remotes also use Bluetooth HID.

-From Wikipedia

If you are having problems pairing, try out iPhone and iPod touch: Third-party headsets, headphones, and car kits