CAR SHARING SITE

I want a site to offer people a simple way to share their car in the trips they do. There is a site that I really like the style: [login to view URL] The basic functions I want to create are: 1.- Registration process 2.- Login Process 3.- Offer a Ride 4.- Search for a ride. 1.- must be as simple than on the orig site, with the option to Facebook register. 2.- Login process easy + "remember me" option 3.- On the site people who has a car and a planned trip to somewhere enters the details whan you enter the cities a listbox must open to show the matches with the text you entered, and a google map on the right ofthe page must show the city. also there must be an option to choose highways or no higways, ant to add middle cities of the trip. in order to exactly show the route the driver will follow on his tryp. 4.- when searching for a ride, there will be the option to create an alert. (as I know that must be a backend software wich querys the database to find the rides to send emails. May be it could be implemented in a way that when somebody creates a new ride, make a query to the alerts table, and if some alert matches, then , on the POST execution, the mail could be sent, so we avoid have to run an backend software. I accept opinions. All the Backend options of managing the database have not to be implemented. I will do it with VB or similar. The database must be MySQL and I accept PHP or ASP.NET, but preffer PHP so it can be easily hosted in a Linux Site. There is also a good option in the site to search cities near the orig or dest city. If this is difficult to implement, you could offer it as an option. thanks Xavier