Ah, May. It's the busiest time of the year, between season finales of your favorite series, the network upfronts, LA Screenings, and the massive culling of series chaff. Yet this year, networks are launching several new series at the end of the month. Some will be little more that warm weather burnoff while others make me salivate (CBS' Pirate Master , for example). Then there are the ones that I'm curious enough about to want to watch more than a single episode. ABC's new series Traveler definitely falls in the latter camp. (Originally intended to air last fall, ABC cut back the action series' episodic order from 13 episodes to 8 and pushed the launch to summer.) Traveler isn't perfect but it is intriguing, offering a respite from mindless reality shows, drama repeats, and whatever the hell VH-1 is airing. For those of you up not to speed, here's the skinny. Three best friends, newly freed from the shackles of grad school, girlfriends, and student housing