How many dimesions are there in the universe/space?

[Tormod]

Originally Posted by Bo

The bowling ball picture is something we can understand and therefore it is insightfull; However you should keep in mind that it is not what realy happens. space gets curved; but not 'in a certain direction' as is the case with the bowling ball.

Well put, Bo! The question I sometimes ask people who wonder about this is "Into what does the gravity well extend".

[Eclogite]

It has been suggested that we may live in a Universe consisting of only two spatial and one temporal dimensions. The illusion of the third spatial dimension is a consequence of the Universe's holographic character.
I suspect a Google search for holographic Universe would turn up some interesting links on the topic.