sciencegeek: If you want to share the experience of singing a song - then do what it takes to get the job done. Use the book, but maybe try to lean on it less and less if you can.

Yes! That's a wise and reasonable policy. I'd put it a bit more assertively: strive to reduce your dependence.

When learning a song, I mostly refer to the sheet before or after singing, either to get the words in mind, to fill what I totally blanked on or to ensure that what I sang was correct--I seldom sing directly from the page. I maximally exercise my recall, using sheets as a last resort. When "performing", mostly I don't use sheets at all, and when I do, I refer to them as little as I must. Obviously, one has to read line by line when cold-reading, but there should be good reasons (yes, there are some) for choosing such a song to sing. Otherwise, you might need to refer to the lyrics, but you should only do so to prevent lapsing; you shouldn't be reading line by line as a general practice.

And Pip is right (if you ignore the nevers): finding that you actually can sing straight through without the safety net is liberating and builds confidence. Blanking is NOT the worst thing that can happen to a singer: there's also skipping or repeating verses, flubbing the tune, Freudian slips, choking up, sour notes, dropped trays, open flies, hecklers, beer bottles to the forehead.... You survive, you learn to cope--and you learn what to do when it happens again (as it will).