Check this out http://matt.might.net/articles/how-to-native-iphone-ipad-apps-in-javascript/
Unless your custom wheel is as native feeling as this web app I will argue for a native UI instead: http://cheeaun.com/blog/2012/03/how-i-built-hacker-news-mobile-web-appIn fact that's the only web app I've ever used that I like & don't feel like I have to give it lots of slack 'because it's a useless webapp'.