For a long term investment, you can buy USO on dips, but I personally think that Bush will pull some Saudi strings to get oil back into the $70 range from $105 because these prices raise questions about a Republican presidency and he is worried about his "legacy." And I do believe he is that simple minded.
From a technical analysis standpoint, I think oil is a little overbought here. There is no rush. You aren't going to miss a big move in the near term because you have already missed the big move in my opinion.
Oil or Energy shares are a good hedge against inflation and the falling dollar. As long as the dollar continues to fall , oil will rise as its currently priced in dollars.