This may seem like a weird question (hehe) but how are you preparing for the Half-blood Prince release? I know many fans read all the books before a release (I heard a lot of people read from the Philosopher's Stone upto the Goblet of Fire just before the Order of the Phoenix was about to release). Are you planning to do the same? A lot of people have parties... some right before the release, or right after. Are you thinking up a bash?
Also, just as an additional question, how are you getting your book? Have you ordered a copy online, saved one at the bookstores (Barnes and Noble, Borders Bookstore, and Walden Books, among others, have a system where you can have them "hold" a book for you, and you come and collect it on the day of the release), or are you goign the old-fashioned way and staying in the line, waiting for midnight?