Hello. I am completely new to mobile WAP/WEB sites development. I am analyzing some mobile content delivery platform which I am going to implement. My question is: Is it possible to uniqly identify the specific mobile device that is visiting the site whether it is a WAP 2.0 device or a smartphone with a usual WEB browser? And later use this info to know that this specific device has already been on my site. I see some means: 1. Usual telephone number (MSISDN) which is I suppose is a confidential information and is not passed to a WAP/WEB server. I think I cannot get it "for free". 2. IMEI of the mobile device. This looks interesting but the question is IS the IMEI passed somehow to a WAP/WEB server from a mobile device? If yes then I can save it and later identify a device against my IMEI DB. 3. Any other means which I do not know yet? Sorry for chatter but I am not new to software development. I first google then ask but now I just don't understand from what side to come to this problem. Thanks in advance, Grigory.