The World's smallest color spy camera is really really tiny; approximately 1" x 1/2" in size and transmits color video up to 1,000' in the line-of-sight directly to TV Channel 59. This small spy camera also claims to  work or up to 10 hours non-stop on a 9V battery.  It's available from Amazon for US $259.99 currently.

Oh, BTW  make sure you also see our list of the "sneakiest" spy cameras money can buy.