Find exact gps location of desktop user

Hello I want the experts help to implement the following features in my project. The code can be in any one of these languages (PHP, ASP.NET and JAVA, JAVA SCRIPT) Case 1 : Find Browser IP Location. The desktop users will connect to our web application from their homes. The moment they open our home page, his current location should be displayed on the home page. Please note it should not be the city name. It should be the user location name. You will get this solution only if you can read the IP address of his home router, not the ISP router address. Case 2: Convert postal address to gps coordinates. There will be two sets of data items. 1. User provides his current location postal address. 2. User Location GPS coordinates (Long, Lat). Expected Functionality here is : 1. User provides the post address and you find his location gps coordinates. 2. Give a provision to the user to open google maps and find his location, based on his confirmation of his location on google maps, the system should automatically fill the fields in the first and second data sets. (address and long,lat values) Case 3. Show google maps with exact user location. A separate box with google maps should be shown and based on the latitude and longitude values read from the user database, the exact location should be identified and highlighted. Case 4.. Road distance calculation between two gps coordinates. To my knowledge, distance calculation will be done in two ways. 1. Air Distance (Not required) 2. Road Distance (This is required) Accept input for both "To and From" fields, display its postal/google maps address below and and display the road distance between these two points. With my limited exposure, I can only think of google maps and google APIs as a solution for the above cases, if you do have any other solution for the same may please share it. I am open to any solution as long as it is economic, less dependency and easy to manage. I appreciate if you had already done similar things and can share those links along with your proposal.