late to the party... have you seen skybell's version?
http://www.skybell.com/product/skybell-device/
got one when they wanted 150... I don't think I'd pay the 2 bills they're asking now. wireless to iphone only.... or ipad. I had to replace my doorbell because one of the delivery guys used a pen to push it and the pen broke through the plastic. Needed a new doorbell switch so I thought what the heck I'll spring for this... took 9 months as they were just developing it...
my iphone rings when someone pushes the doorbell and I can actually talk to whoever is at the door... At home it's also on my ipad so I have that near the TV and can decide if I'm going to answer the door or not. You can do a quick check anytime to have a look around. For months though when my phone rang by the time it got connected through the net 30-45 second rolled around. I don't know what they did but it connects now in about 10 15 max...
this is going to be old news once I finish my security camera project on the house.