Things I always bring to (IN TO) the parks:
Bubbles and color book/crayon...necessities for waiting for parades or sit down meals
pennies and quarters for the penny machines
towel
extra socks for the kids (they always get theirs wet) packed in a ziplock bag so (a) they don't get wet and(b) so I can put the wet ones in there
rain ponchos (I learned this trick through the u.g. it truly becomes a sea of yellow when it rains. I was able to keep track of my family with the pink and blue)
mini first aid kit and ibuprofen or tylenol
DD's blankies
A few pens, in case I need to write something down, to play word games with the boys, in case we lose one of the autograph ones
gum
sunscreen
hat (for me for sure, maybe for the others, too.)
sweatshirt/pants
(Now, for the last number of years, we've traveled with a stroller, so all this stuff would fit in two smaller bags on the bottom of the stroller. Recently, when we traveled w/out the stroller and it was two backbacks.)
Things I bring with on vacation:
plastic bags for transporting wet clothes
ziploc bags for a variety of things
fanny packs for all three kids
walkie talkies
extra bathing suits (I can't stand wearing a wet one)
plastic cups (can't have glass down by the pool, and they're usually glass in the rooms)
bath toys for DD
and usually an air mattress (this saved us once, as they were "out" of two bed rooms!)
oops--edited to add---nightlight