Our games see a fair bit of ritual use. Water breathing, water walking, comprehend languages, hand of fate, detect secret doors and knock are all favorites.
Creative uses:
Floating disk to carry a captured enemy while trying to evade pursuit in a mountainous area. The disk allowed them to move at their full speed, rather than getting slowed by hauling around 220 lbs of unconscious baaz draconian.
Make whole to repair a good shrine, while staving off a zombie assault. The party wizard was 9 minutes into casting the ritual when zombies started battering their way into the shrine from two entrances. The rest of the party had to hold them off for 10 rounds (1 minute) while the wizard completed the ritual - which would repair the altar, resanctify the area, and permanently keep out the zombies. Each round was a tough decision: do I keep casting, even though my buddies are in desperate danger... or do i stop casting, join the battle, and hope that our group can take out a bunch of zombies in straight combat?