You're wellcome,
OK, if You insist on going unnoticable then You will likely need spy micro cams and posibly micro DVRs.
Quick google search for micro + camera
http://www.google.com/search?q=micro+camera yelded dime size wireless or eyeglass cameras for ~$100 all with sender receiver & batteries and cigarette box size DVRs that record to SD cards with camera kit for ~$200.
I don't see why You couldn't feed that video signal to X10 software or use a splitter and feed to both X10 and the DVR. You would get one of the cheaper X10 kits that don't include any cameras, but only the video capture hardware and software:
Vanguard internet software with kit (3 kit options):
http://www.x10.com/promotions/va11a_ed_ex_0716_2.html
USB adapter & camera kit w/Software (different than Vanguard):
http://www.x10.com/products/va11a_ed_mcpw_fb259.html