In class we were working with a web service. Since this was a simple class exercise, all the web service did was sleep for 3 seconds. When we added the web reference to the web service into our class library (so we could call said web service) we got a declaration that looked like this:
WebService.Service srvc = new global::WebService.Service()
What the heck was that "global::" bit there for? It was actually in the Intellisense.
I found this in MSDN2 - http://msdn2.microsoft.com/en-us/library/c3ay4x3d.aspx
Basically you're preventing confusion in the namespaces. Fair enough. Cool that Intellisense detected that this keyword was needed, but I'm not sure why my tiny listtle test app needed this since I wasn't using any similar namespace. The namespace of the project I was using was actually "AdvancedWebParts". To my knowledge, I wasn't aliasing away my namespace. I'll have to look back at the code.