Certain methods for obtaining beliefs are better than others, though. It turns out that one method gives you a ~4.5 billion year old Earth, but also cellphones, computer networks, plentiful food, eradication of many diseases, spaceflight, lolcats, and so on an so forth. The other method gives you an Earth that's as old as you want it to be, and good feelings, and... what else ?

One of the many problems with solipsism is that it lacks an application.