Slug and Snail Problem? Lettuce Help?

Have you ever bumped into the night life of your garden? It's like discovering as a kid that your parents eat ice cream Sundaes when they think you're asleep. Except in my garden it's slugs and snails indulging in my sweet seedlings. I read online to handpick them by "torchlight" which sounded so much more adventurous than a boring old flashlight, that I gave it a try. What I found was a whole city of activity: worms (now I know why they're called night crawlers) "sunning" (is it "mooning?") themselves, sow bugs (rolly-polly bugs) roaming over the detritus, daddy long-legs skittering through the shadows, and of course slugs and snails working their mucous-y flesh toward my plants.

Well I handpicked until I'd collected about 20 snails (I am not squeamish about them, but if you are, use gloves and prepare yourself for the hiss as their hydraulics kick into gear) and squished some slugs (I'll live and let live only to a point:). I noticed that the snails have left alone my dill, onions, garlic, spinach that I surrounded with sand, and most seedlings that had copper (wire or penny). My green beans are currently a favorite target, though. They love lettuce, but I haven't had an issue when using copper. Last night I watched snails cross the copper wire I had around the green beans and I'm pretty sure one flipped me off with its little antennae. Diatomaceous earth I've witnessed deterring slugs. Both copper and diatomaceous earth are more costly, and the copper doesn't wash away with watering. I just read a suggestion to use plastic bottles cut jaggedly into rings and around the seedling. Also surround attractive plants with deterrents (onions and garlic). This summer I plan to make escargot before my snails are going going gone.

At the Community Garden this Saturday morning we're planting 150 seedlings (9-10am) and could use your help with that, as well as weeding and harvesting lettuce, radishes, spinach, etc.