Become a tic-tac addict
Become an expert on something nobody cares about
Befriend flies
Behold the truth
Bite every other nail
Bite your pinkie
Blast hip-hop music through town
Blink a lot
Blow bubbles
Blow bubbles with bubble gum
Blow on a beer bottle
Blow on a blade of grass
Blow spit bubbles
Blow up a balloon until it pops
Boil ice cream
Boldly go where no man has gone before
Bother a sibling, profusely
Bounce a potato
Braid your dog's hair
Break into a friend's house and clean it
Break some rules
Bring a Furby to school
Bring dog treats to the park and meet 25 new dogs
Bronze your sister
Brush your teeth
Buff your cat
Build a house out of toothpicks
Build a house with ice cubes
Build a model of the Eiffel Tower out of Belgian waffles
Build a pyramid
Build a tree house in the middle of a field