Yahoo has acquired yet another social software site, according to TheSocialSoftwareWeblog, which is reporting Yahoo’s purchase of upcoming.org, a collaborative calendar and event listing service. Users of upcoming can search for events by topic (for example "social software") or location (for example "London"). I wonder what plans Yahoo has to incorporate this into it’s search, Yahoo Groups and/or Yahoo 360… and how they might be able to use the functionality of upcoming to enhance their other recent purchase, flickr.