This is one area that non-programmers can very easily help out in. Even though we haven't decided on SMS as the best interface for this project, I'd like to start a parallel thread that explores this option in the event that it turns out to be the way to go. I'd like to speed up the process and involve everyone as well, so a parallel thread seems like a good idea. The problem we're seeking to solve is this: - what exactly do users type in their SMSes while asking for, or updating, petrol prices closest to where they are? The system will interpret these SMSes and send back a result accordingly. The "language" we're defining needs to be: - simple and intuitive (makes life easier for users) - clear and unambiguous (makes life easier for the system to know exactly what the user meant) - brief (needs to fit in a single SMS) There's only one way to know: real-life testing/simulation. Since everyone on this list travels within the city (and passes by multiple petrol stations every day), let's harness our efforts and see what would work. Let's pretend PetrolTracker is a fully-functioning system: how would you use it? What messages would you send it from your phone, and what responses would you expect? Since we don't yet have a system to receive the SMSes, this thread will do for now. Reply to this thread with what SMS messages you would have send to the system, and also inlcude the response(s) you expect. To try and simulate reality as much as possible, try and type out the message in real-time, i.e. as you are driving/passing by the petrol station. This will help test the practicality of the proposed system. I suggest you save your SMSes as a draft and type them out in this thread... the more the merrier. What do you think? Saidi