Just a heads up that the latest software upgrade to vBulletin 4.1.11 adds a mobile-exclusive theme for any smartphone users (iOS, Android, BlackBerry, etc.) which makes the site easier to navigate.
The forum was made compatable with Tapatalk a while back before this upgrade but for those users who do not want to purchase/download the Tapatalk app, you can just use this alternative.
Not sure which is better than the other, so experiment!
EDIT: If this isn't auto for you while on your phone, just scroll to the bottom left corner and pick the mobile them as your style!