I've put together a pie chart of all the gear I'm planning to carry, almost down to the particular item. I'm pretty astounded at the weight already, and I'm looking for ways to cut it down before I start making the intended purchases.
It's a pretty good way to trim the fat where it counts. No use spending an extra $70 on a lightweight stove when your pack is the real culprit.
Some of you might already do this, but I like to point out the obvious for us slow and simple people.
-Of course, this will probably all go out the window during the first week on the trail!