The Bay Area has a long history of underground cartoonists, from '60s freaks like R. Crumb and S. Clay Wilson to '80s "second wave" artists like Dori Seda and Dan Clowes to current wonderkids Adrian Tomine and Ariel Schrag. Before long, Oakland native Jason Shiga will be added to that list. For the last six years, Shiga -- a Cal grad with a degree in mathematics -- has been unleashing some of the most involving comics around. That's involving in both a literal and figurative sense. Shiga crafts "choose your own adventure" comics in which the reader follows cues leading to a number of different endings. His latest book, Meanwhile..., is 72 pages long and can go in an astounding number of directions. It begins with a boy (and the reader) deciding which flavor ice cream to buy. Choose vanilla, and he takes his cone home; but choose chocolate, and he's launched on a wild journey full of doomsday devices, evil twins, time machines, and giant squid. If the book's complexity is too overwhelming, Shiga also does more conventional narratives: He won a 1999 Xeric grant for Double Happiness, a touching tale of an Asian-American boy who never fits in.