I saw a theme this morning as I perused the various other tech sites: Hulu invites! Hulu, the video-streaming partnership between News Corp. and NBC, is throwing open its doors to many early adopters by offering up thousands of invites on several tech sites. If you haven't gotten a chance to play around with Hulu and want to see just what the hell Paul Boutin is complaining about, here's your chance. GigaOm, Read/WriteWeb, TechCrunch, and Mashable are giving away 2,500 invites each. All, we note, are clients of Federated Media, John Battelle's online-ad network. Coincidence, conspiracy, or just part of a future Hulu advertising campaign?