JustSpotted plans to sift through people’s tweets to identify those that claim celebrity spottings, and then to place those celebrities’ whereabouts on a map in real time. It would be similar to the now-defunct GawkerStalker, but it would be faster. (It’s not a novel idea. Last year, start-up OMGICU proposed to do the same thing, supported by text messaging and tweets, except its service requires active user participation rather than data-mining the whole Twitter community like JustSpotted will do.)