A post by the gentleman from Waterloo conflates absolute pitch with literacy in conventional notation.
I have the latter, but not the former. So, I find sheet music quite useful--in particular, because I know how to read it, it's a much more efficient way for me to learn a new piece of music. And no, it's not a distraction: As a beginning thereminist, I can play Handel's "Where'er you walk" (from Semele) with reasonably accurate pitch, whether I'm looking at the printed music or performing the tune from memory. (Yes, I need a reference pitch to start--but once I have it, I can get through the whole song.)
This isn't to preach that everyone necessarily ought to learn to read... but if you're going to perform tunes accurately, you need to be able to hear (and reproduce) different melodic intervals, regardless of whether you've learned their official names ("minor second," "major second," etc.) or what they look like on the printed page.
Our friend from California correctly points out the importance of this in playing just about any instrument EXCEPT piano, harp, or any other instrument for which all the pitches are fixed from the get-go... which constitutes an important shortcoming of these latter, even if they do make it easier for beginners to pick out a tune. (Think about it: if you really want to tug the listener's heartstrings, you DON'T assign your big melody to a piano, or harp, or organ, or marimba... nope, you assign it to an oboe, or violin, or 'cello... that is, something that can inflect the pitch for proper intonation and expressive effect.)
Pardon... getting back to the topic...
Of course, laying pages flat atop my Etherwave isn't the most satisfying arrangement... if I can find the time and proper materials, I might construct a lightweight music rack to sit atop the instrument (sorta like what one finds on a harpsichord).
In summary: The question of whether or not to use notation is entirely separate from the issue of ear-training (which you need to do anyway, whether formally or informally, consciously or unconsciously).