dude, let me say for one you've been nothing but contributing and helping everyone out here at this forum, I am still a part time lurker and I could honestly tell you I am going to bomb this exam.
However, you need to stay focused and there's a scoop for you. Rumour HAS IT that the gmat exam has itself a "timer" for every question. e.g. if you get the 1st q right in 2 mins, but spend the next 10 mins on the 2nd q and eventually getting it right. your mark would still go down! why? because the exam thinks u guessed the 1st Q and the 2nd is a true reflection of ur quant ability. My advice is spend about 2-3 mins on each question. That's it. move on. Who cares, according to PR, it might even be an "experimental" q.
For Verbal, I am opting for the same rule come dday, but I am going to approach it very systematically. i.e. 3.5 mins for harder Qs and 2 mins for easier ones, even if I knew the answer after 40 secs (on a RC purpose Q), i'll be doing the map thing as suggested by manhattan/PR/Random ppl.
I seriously don't think the gmat is an exam which assesses of intellectual ability as much as assesses on how well you allocate your time and how critically you could make rational decisions given the limited time you've been provided. After all, its NOT a math and verbal test, its a so-called "managerial ability critical thinking test". For me, there's no right answer on the gmat, only the answer that bears the least amt of risk and that, at the end of the day, is what managers are tought to do or a manager's intuition in a global economy. that given, there was another rumour that a professor at HBS took it last year for fun and got 550 as well. There you go.
Having said that, READ this forum like its ur bible! there's some seriously valuable tips from forum ppl here. Jingchan is a farkin inspiration, especially with his 100 q a day routine in which i am following closely and there's some seriously talented people out there on this forum. I think you are in good hands my friend.