The SOLIDWoRKS World hashtag is something that started way-back-when during the early days of Twitter. You can still check the old tweets under #SWW09, which supposedly trended on Twitter during SolidWorks World 2009. Many years later, many more services now support hashtagging.
SOLIDWORKS World 2015’s hashtag is #sww15, and it is already being filling up with useful information on Twitter and Google+. Check it out, and keep following them for the lastest!