How to develop an application to Mobile Devices Browsers and Laptop Browsers?

[eluser]BrianDHall[/eluser]
I've noticed that most big companies say 'screw it' with auto-detection and instead just use custom tailored websites. So you get things like mobile.yahoo.com, or google.com/m, etc. They seem to have found that trying to do it magically is tragically hit or miss, so it is just easier to have a dedicated website to special devices - and then sometimes they can try to do auto-redirection based on user agent and such, but for whatever most companies seem to have found it is just preferable to let the user tell you what they want instead of trying to guess.