Phoenix is lousy with little theaters, and most of them are a revolving door for would-be thespians who aspire to community productions of Neil Simon comedies. These petite playhouses cater to theatergoers who'd just as soon rent videos and don't want to be troubled with shows they haven't already seen. Then there's teeny Is What It Is Theater, a group of Camelback High School alumni who for the past five seasons have pushed the arts envelope with quirky and rarely produced shows that we'd never see otherwise. Last year the kids at Is brought us the seldom-seen Gingerbread Lady; a tidy take on What I Did Last Summer; and a risky adaptation of Orson Welles' radio drama The War of the Worlds. While not every one of this tiny troupe's productions is a winner -- its production of hoary old The Curious Savage was a reminder of why no one mounts this show anymore -- it's set a standard for alternative but still commercial theater. More impressive is the fact that the troupe has done it all on a shoestring.