Handset Detection is a web service which lets you Detect Mobile Browsers. It can identify over 53,000 mobile devices. This is particularly useful if you want to target the growing market of mobile users. The API features strings for click-to-call and send-SMS functions, mobile device properties and geo-location information (e.g., ISP, country, latitude and longitude, etc.)

Other Projects Include Detect Mobile Browsers with PHP, Detect Mobile Browsers with Java, Detect Mobile Browsers with ASP.NET