>Using OpenTable, Urbanspoon or SeatMe , diners could see available time slots and make a reservation online or from their smartphone without the hassle of calling the restaurant, and know that their table would be secure.
How is calling the restaurant a hassle? Especially when the solution is to use your phone to look the restaurant up online?
Maybe it's the cranky old man spirit in me, but I call restaurants every time -- I hadn't even heard of these sites. I didn't know that this was a need people felt needed fulfilling.