Well it depends what you want to record.
If it's a true point-of-view then you have a problem finding something really unobtrusive.
Unless you can camouflage it in your clothing ... but then it's not really pov as it's not filming where you are looking.

There are lots of small cameras...
http://www.spycatcheronline.co.uk/ch...era-p-622.html
http://www.elmo.co.jp/suv-cam/en/index.html
http://www.microspy.com/acatalog/Bod....html#aButton1
http://www.spygadgets.com/undercover...es-camera.html

Seems that undercover investigation supply shops can sell all you need - at a price !