For those that want a better experience, assuming the phones themselves don't already scale the forum, there are mods that exist that when they detect a mobile phone, they will display the forum in a different format to that user.
I know a couple Android forum communities, as well as the LU Forums, use a mod called Tapatalk, but I've never used it myself, nor have I installed it on any forums, so I don't know how well that one works out.