This is what my portfolio looks like at the moment. It is a box that contains sleeves and some books and a cd cover.
When it opens up it looks like this:
I think the box looks really nice when it is displayed like this, but it's really unpractical to carry around, so I'm thinking of changing to a 'book'-type portfolio.
I am also going to bring my cute business cards from moo.com, hopefully I can do some networking!