Consult [/url][url=http://lagmonster.org/docs/vi2.html]http://lagmonster.org/docs/vi2.html for more, I found its a pretty good reference.
However one option seems understated. If you want to delete everything from the cursor to the end of the file you'd do (while out of INSERT mode):
Code:
dG
The d tells vi to delete, the G tells vi to go to the end of the file.