Creativity is helped by visuals to see what's around them. Location could help.

Get a chainsaw artist in and carve up some art. Weave a giant spiderweb with wire and crystals between them. Use them as center poles for a huge double umbrella kind of shade. String up a hammock between them- attach in a crossbeam and hang a swinging bench. Use them for mounting bat houses or bird houses. Build a crazy treehouse with them as the base poles. Build a fake pirate ship around them with them as the masts. Set up a double tetherball court. Set up a tilting ring and race with lances to see who can win the most- running or steed of choice :)

Run vines up them. Climbing hydrangeas will climb pretty high.

Residential Landscape Throughout The Growing Season · More Info

Mount a bunch of birdhouses on them.