At this time, there are several options to get a mobile version for your store. If you know any others, please send to sales.
1) BCS Engineering are offering it as a custom add-on (last time I checked, it did not look too professional):
http://www.bcsengineering.com/store/mobile-mod-for-x-cart.html
2) X-Cart iPhone and Android Optimized Theme from mercuryminds
http://www.mercuryminds.com/product/x-cart-iphone-and-android-optimized-theme.html
This one looks good but we did not use it for anybody yet.
3) mobi-cart.com (http://www.mobi-cart.com) was working on X-cart integration but I did not see a complete add-on/package yet.
