Apart from all the times we've been back, you mean? Not manned, granted, for various reasons not connected with technological limitations, but I hear NASA has plans for that some time in the next ten years or so. Interestingly, they intend to use broadly the same designs that Apollo perfected.
At the age of five, Skagra decided emphatically that God did not exist. This revelation tends to make most people in the universe who have it react in one of two ways - with relief or with despair. Only Skagra responded to it by thinking, 'Wait a second. That means there's a situation vacant.'