christ another thread pulled to bits by people debating ethics. its legal, people enjoy it, get over it.
i think you'll find if you look into it hunting trips in africa do an incredible amount of good for conservation, the animals have to be culled anyway to maintain sustainable and healthy populations and the proceeds are often used to set aside more land as game reserves.
for example, rich bloke goes to africa and pays $6400 to hunt a kudu, oryx, wildebeest and an impala. thats his limit he can oly hunt one of each and there's no guarantee that he'll actually get them. he obviously wants to get a nice trophy so the guide's pick out the animals that have impressive horns and antlers, which tend to be the old male animals. by hunting the old males the young males can mature and mate with the females, resulting in a stronger population and more variation in the gene pool.