It doesn't really matter what extention really is used IMHOJust live with .PDE....
try using Processing (Arduino's sibling environment) and see how easily you can live with clicking on sketches and have the wrong environment come up.
Please enter a valid email to subscribe
We need to confirm your email address.
To complete the subscription, please click the link in the
email we just sent you.
Thank you for subscribing!
via Egeo 16