HitMeUp is all about hanging out. At the very core there is the 50 character status. In order to hangout with a friend, you only need to know where they are at. This can be announced in < 50 characters. Hastags are primarilly for locations. #theFooBar links me to others at or going to #theFooBar, and it can used via sms. A smartphone/web user can tag GPS coordinates for that location hashtag.
Also, I can also say who I'm with @Friends Name
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