Surf already exists-- it's called behavioral targeting. Of course, no one (not even facebook) is stupid enough to directly report this information back to the user or the user's friends, except in the form of targeted ads. <p>Image Scan actually sounds like a pretty good business plan-- once again, for ad targeting. Although there are some quality issues--- do you really want your ad showing next to someone burning one of your shoes, or a picture of a sweatshop worker?<p>Locate-- facebook might not be working on it, but google definitely is. <p>Diary-- livejournal. fb notes. 'nuff said.<p>Receipt-- Beacon on crack. Marketers have been chasing the holy grail of tracking customers purchases across all channels. If you've ever given a "source code" or "catalog code" when ordering from a paper catalog, that's what you're doing. Cross-channel microtargeting is the future! <p>One wonders if the credit card processors are doing the kinds of under-the-table clickstream-data types of deals that the ISPs are doing.