In my continuing quest to find and post to long dead threads, I present this post.
If you like flying ships in your game (and who doesn't) a fight between PCs on the Ship and an aerial creature (like said Dragons) can be really interesting. The dragon can snatch PCs off the boat and drop them, attack at long rang with spells and breath weapons, or the dragon can simply sink the boat sending the PCs falling to their collective dooms.
Likewise, have flying opponents attack PCs while they are climbing (a rope, mountain, anything high will do). Cliffs, ledges, flying things, and long drops make for some interesting combats.