there is one gmail account within each google account: a google
account consists of a gmail account and any other google services that
you use with the same login information.
to delete a whole google account (gmail, docs, blog etc.):
- settings --> accounts --> google account settings
- My products - edit
- select "Close account and delete all services and info associated
with it"
in this case everything that you could access with that particular
login name will be deleted forever
to delete only the gmail part but keep all the other services
associated with that google account:
- settings --> accounts --> google account settings
- My products - edit
- select "Delete Google Mail Service"
in this case you'll have to give another non-gmail email address that
will be used as your new login ID to the rest of the google products
