A few months ago I began using jQuery Mobile for a couple of Web projects. If you’re not familiar with it, jQuery Mobile uses CSS and JavaScript to make an HTML5-based site look and act much like an iOS app. No native programming required; nothing for the user to download and install. It’s a pretty amazing little package, which is not unexpected given how great jQuery is. If you’re curious to learn jQuery Mobile, check out this excellent tutorial written by C. Enrique Ortiz and posted at IBM’s developerWorks.
The only thing I’ll add, which is not mentioned in the article, is that jQuery Mobile is a logical choice in situations where you’re making a mobile version of your Web site that’s separate from the main version (and, presumably, redirecting mobile clients to it). Whether or not that’s a good policy is of much debate these days.