I don't know a prepackage solution but it is easy to build one.
Axis has a very small encoder that you can use with your favorite covert camera.
You can combine 2 cameras with the SV-16 NVR from Genetec, it's a mini NVR ( 4 x 4.5 x 1.05 inches ) that consumes only 6 watts and includes a wifi 802.11g and 2 ethernet ports.
http://www.axis.com/files/datasheet/ds_m7001_34065_en_0907_lo.pdf
http://www.genetec.com/Products/Omnicast/Pages/sv16-en.aspx
Good luck!