24/7 keyless entry for any paying member. Security cams in place recording data off-site

We lease the building so we are limited in what we can do as far as automating the door locking mechanism. If we do manage to figure out a way to unlock the doors with something keyless, how do we make these keyless dongles, e.g. RDIF or NFC? An SMS-based interface might provide a keyless entry method that doesn't require any fabrication or additional costs per member. The member will simply interface with the door lock over SMS on their own phone. Google Voice would be an easy way to SMS interface with an Android-based locking/unlocking device. We're not the first to think of this and it appears that their terms dating back to Dec 2009 do not allow such 'screen scraping' methods. The newer Google terms that go into effect March 1 2012 have the same pertinent sentence:

"Don’t misuse our Services. For example, don’t interfere with our Services or try to access them using a method other than the interface and the instructions that we provide."

We could and should manage the dongles (or cell phone numbers of allowed keyless entrants) in the wild with the wordpress user database. We already are using the wordpress user database to manage paying members.

We have a Zmodo 8-camera security kit but the video flickers badly and we believe it is because we may have the wrong power supply for the cameras. We also have two different standalone webcams that detect motion and another standalone HD webcam.