Not one but two logic summer schools for undergrads this year:

Carnegie Mellon Summer School in Logic and Formal Epistemology
June 8 to 26, with courses by Steve Awodey (Categories and Structures), Teddy Seidenfeld (Decisions and Games), and Jeremy Avigad (Logic and Formal Verification)
Apply by March 15

UCLA Logic Center 2009 Summer School for Undergraduates
July 13 to 31, with courses by Henry Towsner (First-order logic and Gödel’s incompleteness theorem), Justin Palumbo (Forcing and independence in set theory), and Isaac Goldbring (Non-standard analysis)
Apply by March 30

Both of these are free, and UCLA promises to even pay a stipend!