Complex sentence: These include Last.fm, Dopplr, Songkick, SocialGO and 7digital--who tend to gravitate towards Old Street roundabout, popularising the term'Silicon Roundabout' to describe the area, referred to by Prime Minister David Cameron in a speech in November 2010.
Split into simpler sentences: These include Last.fm, Dopplr, Songkick, SocialGO and 7digital. These companies have tended to gravitate towards Old Street Roundabout, giving rise to the term "Silicon Roundabout" to describe the area, as used by Prime Minister David Cameron in a speech in November 2010.