I've used toptable.co.uk for that which is pretty good (most of their restaurants are in London but I've booked places in Rome succesfully too). Key points are

I've used toptable.co.uk for that which is pretty good (most of their restaurants are in London but I've booked places in Rome succesfully too). Key points are good description of the restaurant, accurate sample menus, pictures and reviews from other patrons. I think just the website won't sell unless you get the selection volume of toptable; but a turnkey reservation system + web front end would be helpful because a restaurant can link to you and let you take over the reservation instead of having someone have to answer the phones. Make it subscription based to minimize up-front cost; heck even offer restaurants to host an easily-created mini-site they can use as their official web page; there are loads of places that don't have a website but maybe if all they have to upload is a few pictures etc. you could go even further here allowing easy online menu creation, export to pdf, cost calculation, whatnot. toptable is good but not great because they usually don't integrate with the restaurants' systems, so they have people sitting and calling the restaurants to reserve, so there's lag between reservation and confirmation (and 50% of the time in London my first/last name end up swapped or mutilated) A local service here in DK is dinnerbooking.com which gives you the actual dates & times something is available. I am far likely to book a table at such a place than one where I have to phone them and hope to get through. Alas they're a pretty slow Web 1.5 site.