How do you shorten a video so that you can send it in Email?

I have video that I have taken with my digital camera. The file size is too large to send via email. I don't know how to shorten it into a smaller clip so that I can share it. Can anyone help me?

The correct word is not shorten. Its compress. U can change the file format to a lower sized format in that case. Maybe a wmf mp3 video. How ever even this will drop the quality of the file immensly.