The lens in question was a Canon 70-200 2.8 (for those of you into photography look it up - it truly is incredible). It's not my regular lens, in fact I only hire it for special events.
And yes, it is a monster and really heavy so my arms do get sore!!
The great thing about this lens is it allows me to shoot from a distance - that means at an event like a naming ceremony I am not disrupting the view of the guests when I am getting my photo's. It also creates beautiful bokeh (lights in trees and the like) and depth of field (nice blurred backgrounds).