1) my work - i definitely hold myself to a far higher measuring stick on all things related to work. being early/on time for meetings, having my "tasks" done, and often, take on greater responsibilities, and sacrifice a lot to make sure that my client/cohorts are very happy -- i always look at goals as minimum expectations that i plan and prepare to far outpace.
2) communication in general. unless i know you very well, i can be rather perfectionist about concept articulation, word choice, grammar, and even formatting. however, it's pretty much second nature to me, because i've always been that way.
i'm the same way in presentations and events where i need to present or speak. i am always concerned about conveying my message without failing in some obvious and predictable way.
3) the only other thing that can sort of worry me is others' feelings. i can agonize a bit about others' responses, confrontations, and letting someone down. i feel horrible if my actions wound someone, and would do almost anything to prevent that.
i have lived my life mostly trying to be the classic under-promise, over-deliver motto. i hate it when i'm EXPECTED to meet some high standard, and forced into some role or category that feels either challenging or impossible to meet--usually by someone else's perceptions of my abilities. i prefer to set my own challenges (such as volunteer) rather than others placing me in those boxes. that said, i seldom take on things that i'm not confident i can do really well.
while i do have some real perfectionist tendencies, i am FAR from uptight. i could probably give lessons in NOT being uptight. ; p.