One of ours wrote an interesting article on the topic of Stick Jocks and Paste Eaters on her own blog, Its Dangerous to Go Alone Take This. For purposes of the article she defines Stick Jocks as those who LARP primarily for the combat and Paste Eaters as those who LARP primarily for the role-playing. She also mentions that in her eyes the majority of LARPers fall somewhere in between. She also goes into what each type is looking for in a LARP and how they can interact with others. It is a good read and I recommend taking a look at it.
The site has another good LARP/Realms article up. I know some have seen it already but here is a link to that article as well.