Here is my idea, feel free to steal it or just comment.
I would setup a cloud company that signs up restaurants, venues, hospitality etc..
The company would get virtual email accounts assigned for each seat, table or whatever they sell.
Then anyone with outlook or similar could connect to my cloud network, setup a meeting or appointment and be able to see the availability and book.
If available (which it should be as you would be able to check in schedule manager) you would get an instant confirmation.
This would make it easy to co-ordinate functions, business meetings or even just lunch/dinner with 1 or more people.
Essentially for anyone who works for a big corporate, it would work the same as booking a meeting room.
I can think of a dozen additional functions but the core concept would be having a huge network of hospitality and corporate locations, available easily and managed as an add on to outlook or similar.
No more open table, no more Dimmi. You could see who is attending, you could move the booking, you could even add a WebEx to the event for people to dial in.
so like menulog for bookings.