Mesh08 organizers announced their fourth keynote speaker yesterday and the line-up looks strong. Garrett Camp of StumbleUpon – one of Canada’s leading Web entrepreneurs – will be the keynote speaker for the business stream. He’s joins Ethan Kaplan of Warner Bros., Club Penguin’s Lane Merrifield, and Matt Mason – author of The Pirate’s Dilemma. Camp co-founded StumbleUpon in 2001 with several university friends while he was finishing his degree in software engineering at the University of Calgary. He and a couple of the other members of the StumbleUpon team later moved to San Francisco after getting venture financing, and last year the company was acquired by eBay for $75-million. Camp is still responsible for StumbleUpon’s product design and strategy, and the service has more than 3.5M members. Techvibes is a Media Sponsor for Mesh08 and will be live-blogging from the MaRS Centre.