Thank God this didn't turn into a retarded Trekkie Vs Trekker debate:
A Trekkie to me, is a fan of the show, a big fan, not a casual one. That of course, doesn't mean that every Trekkie is such a big fan that they go to Trek conventions, dress up in uniforms etc. Like previously mentioned, there are degrees. Trekker doesn't exist in my eyes, it's just something that was made up because the name Trekkies had been ridiculed too much. Pussies.