I'm planning to do a week long US "tour" (I'm from the UK) to promote and do research for my startup as well as generally meet and talk to lots of interesting people. While I have several leads, it would be nice to visit startups I have no contacts at that encourage/accept visitors (for example, Twilio - http://www.twilio.com/company/).
What startups are good to visit and like visitors? (Bay, NYC, Seattle and LA are where I'm focusing.) I want to ensure I'll never be bored and, who knows, I might be able to provide some entertainment/ideas/advice, publicity or even some beers to those I meet! (If, for some reason, you'd rather personally invite me and not the whole world, you can find contact details in my profile.)