Know what the iPhone needs? According to John Carmack of Id Software, more classic first-person shooters. So, on his own time and dime, Carmack ground out a free, open-source iPhone port of the classic Castle Wolfenstein (which can be downloaded from Id's FTP server). The only downside: it requires a jailbroken phone.
But Wait! There's More! Carmack is not only working on a similar "iMplementation" of DOOM, but a House of Jobs-sanctioned version of Wolfenstein can now be had for US$4.99!
(Id Software will not be held responsible if you are playing the game in a public setting and find yourself blurting out "Eat flaming death, Nazi war pigs!")