thanks again, everyone. we've done a few things to combat the nibblers:

1. we're loosely saran wrapping and twist-tying the tomato bunches so they're not such easy targets

2. we put some water out for the thirsty squirrels

3. i'm going to try sprinkling some hair on the soil in the pots, i've heard that critters don't like the smell of it

i'll let you know how it goes :)