sed question: remove decoration from each line
 

Hi, how can I with sed take a text file and remove everything after (and including) the @-sign if it can be found?
Say I have this file:
line one
line two@3
line three@332

I want it to look like.
line one
line two
line three

miguel@gold:~> cat /tmp/z | sed -e 's/@.*//'
line one
line two
line three
miguel@gold:~> cat /tmp/z | cut -d@ -f 1
line one
line two
line three
miguel@gold:~> cat /tmp/z | awk -F@ '{print $1}'
line one
line two
line three
miguel@gold:~>

I think the cut version is more efficient than others....