Comment Simply ... (Score 5, Funny) 427
1) Stand on one leg, preferably facing the cell tower. 2) Use your other leg to form a crude counterpoise for the iPhone4's various antennas.
Also, experiments in dry/low-humidity regions which lead to dry/chapped hands may also contribute to your success making and holding a call.
What other company could get away with producing a product like this and succeed?