To pick up on another comment from Tabba's introductory message.

... as opposed to a separate, physical entity in heaven ...

I appreciate that many Christians seem to have this picture of God, but I'm not sure that this is actually what the Bible indicates.  For one thing, we are told that there will be a new earth and a new heaven.  The Greek word used in both 2 Peter 3: 13 and Revelation 21: 1 is kainos - a word often used in the Bible to refer to renewal as opposed to previously unknown (for instance, it is the same word as used for the 'new' covenant referred to in Matthew 26:28, or the 'new' commandment referred to in John 13:34).

As such, the implication is that the earth and the heavens will be renewed - restored to their pre-fall condition.  As such, God is just as earth-bound as He is heavens-bound.  In fact, Jesus and the writers of both the Old and the New Testaments refer to the Kingdom of God and to the Kingdom of Heaven - but these are also said to exist on earth now, as the outworking of Christ's people on earth at any given time in history.