Here's a great Tuna Melt Recipe that uses finely chopped celery.
My sister and I use sour cream instead of mayo, because we don't like mayo. Chopping the celery and then cooking it really brings out the peppery flavor (yup, celery has flavor). Also try chopped/sliced celery as a great addition to stir fry.
Eat cucumbers instead.
Cucumbers are another food that is mostly water and nutrients that happens to take more energy to digest than it actually has, therefore, like our nasty friend celery, it is negative calories.
I eat cucumbers to replace lettuces I don't care for on sandwiches, in salads, and cucumber water with citrus tastes pretty darn refreshing.