Mark Brooks wants the whole web to know that he spent $41 on an iPad case at an Apple store, $24 eating at an Applebee’s, and $6,450 at a Florida plastic surgery clinic for nose work, the New York Times reports. Too much information, you say? On the internet, there seems to be no such thing. A wave of web start-ups aims to help people indulge their urge to divulge — from sites like Blippy, which Brooks used to broadcast news of what he bought, to Foursquare, a mobile social network that allows people to announce their precise location to the world, to Skimble, an iPhone application that people use to reveal, say, how many push-ups they are doing and how long they spend in yoga class. Not that long ago, many were leery of using their real names on the web, let alone sharing potentially embarrassing personal details about their shopping and lifestyle habits. But these start-ups are exploiting a mood of online openness, despite possible hidden dangers…