During the Credits
Views of snow and water shot from a camera mounted on a helicopter flying overhead are shown during the credits of The X-Files: I Want To Believe.
After the Credits (spoilers)
The helicopter’s shot goes from snow to water to then reveal a shot after the credits of Mulder and Scully in a rowboat together waving at the camera. Mulder is shown rowing towards a deserted island. The scene shows how they decided to get away from it all as they discussed earlier in the movie.
Thanks to Murdock23 for the stinger submission!