Unless you're into the whole skin-cancer and premature-aging bit [not that thats a problem this yeared.], summer is best enjoyed inside, with a Netflix account and an Internet connection. Or, inside a conference youre crashing. This weekend brings PAX, a three-day festival of tournaments, panel discussions, and nerdcore concerts, hosted by Gabe and Tycho, the heroes of Seattle gamer-comic Penny Arcade. Its just $30 a day at the door; three-day passes are $50 at www.pennyarcadeexpo.com). With the demise of E3, it's the largest gaming convention in North America, with well over 12,000 geeks expected to attend. All 130,000 square feet of exhibition space sold out. Wil Wheatonyes, of Star Trek: The Next Generation fameis giving the keynote speech.