You know you're near a scientific conference when you see people walking around with mysterious cylindrical containers slung over their shoulders. This is the result of the evolution of the large poster-carrying tube containers. Of course I joined in on the fad myself; My lab has a black plastic poster holder with a strap that we take turns borrowing to conferences. Some have nicer leather ones, some have cardboard tubes, they come in many shapes and sizes. But what I often wonder is, what do other people around town and at airports think we are carrying in these tubes? I know personally that, before I became a grad student, if I saw someone walking around with one of those cylinders, I assumed he was carrying some sort of rifle. Maybe a fishing pole? What on earth could possibly be in there?
They also have a practical, probably unintended purpose; someone carrying a poster tube can instantly be recognized as a fellow conference-goer. It makes for an easy conversation-started, since you know that person probably has some interesting work that they are excited to present and tell you about.
Therefore, I think its a great thing to be a member of this fraternity of poster-carrying conferencers. I certainly see many folks walking around today with their posters, undoubtedly getting ready to take them home. Wear it proudly!