Physics GRE Discussion Forums

Hey guys,
I am currently halfway done my CalTech app, and I'm writing up this "list of publicaitons". Problem is: I haven't got any! If, for example, my name went on a poster that was presented at a conference (the poster was submitted and refereed), then does that count as a publication? If not, where else in my application might I mention this?
Also, whats up with the "List of Significant Extracurricular Activities"? What do they want to hear in this section? I can't really think of any extracurricular activities that are relevant to physics...
-dm

Simply mention, in the list of publications, exactly what it is. So put the poster up there, and mention that it is a refereed poster. Same thing for unpublished works and the likes. Ultimately, you just want to give them all the information you feel is relevant and relates to publications; they couldn't make a separate section for posters, presentations, etc, so they would want you to put everything here as long as you're honest about what things are.