I do not have wi-fi at home and I want to upload video I took into my youtube account. I have generouse data plan so I don't have to use wi-fi to upload larger files like the application forces me.
I am on HTC Desire 2.1
Apps like Tasker or Locale should be able to allow you to turn off WiFi based on what application is running.
See Also: Useful or cool Tasker recipes