I have it mostly memorized, slower with some parts than others. Basically I found it easiest to remember where certain chords are know the notes in the chords. For example, I know the A major barre chord (one form of it) is rooted on the E string, 5th fret. I know that the chord is laid out as below:
5
7
7
6
5
5
From there, I knew the steps were:
1
5
1
3
5
1
And therefore, for the A-major barre chord, the notes would be:
A
E
A
C#
E
A
Knowing my chords and also learning triads helped me to learn the fretboard in a fairly enjoyable manner, without being extremely monotonous and taxing, like Jeff's suggestion. Note, that is
not to say Jeff's suggestion is poor; it's actually pretty good. It just didn't work as well for me as learning chords did.
The reality is that there are many ways to go about learning the fretboard, and you just have to figure out a way that works for you.