Even people in Bleach do that sometimes. Hell, there aren't many Anime's that you see that WON'T have that. BTW I only recall it happening a couple of times in Naruto.

Hinata tried to do that, but she failed, aha (Still love her though!). The whole Hinata ordeal was the first time I've seen something like that, actually.

What Uchiha Barles said. The reasons why characters keep their trump card until the end is because your never supposed to show your best technique to your opponent early in battle, and such. What ever Gai-sensei told Rock Lee before the Chuunin Exams.