I find people do better to memorize 7 notes within a particular finger pattern then trying to memorize every single fret at once. Once the 7 notes are memorized it's easy to apply the principles of altering notes with sharps and flats.

One thing I used to do when I was learning the fret board was to make a game out of it....I would close my eyes and randomely put my index finger down on the neck of the guitar and then figure out what note it was. I found this to be a great mental excercise.

You can also use this same appraoch for ear trainning. Close your eyes, randomely play a note and try to name it.