I'm INFP, but haven't listed myself as one. But I'm open about my type. I just like to replace the 'INFP' under my avatar with little words.
I have never really questioned my type, except for a very short period of time when I first took the MBTI and was trying to decide what my type was. I thought seriously for a moment that I was INFJ, but there is no way in hell. The deciding factor for me was learning that Ps like to 'mix work and play.' You can see me at my university library's computer lab, switching between typing up an essay and posting on forums almost every fifteen minutes. =)
We Ps are cool. Viva la P-eople!