Multiple Web 2.0s from a single account and multiple web2.0s from different accounts. which is best?

My question may seem confusing to some but it is specific. I have always heard that web 2.0s are great. But how do you actually create them? Using a single registered account or by doing multiple registrations through various emails and then posting co…

My question may seem confusing to some but it is specific. I have always heard that web 2.0s are great. But how do you actually create them? Using a single registered account or by doing multiple registrations through various emails and then posting content separately and creating different sites etc? Share your views.