How to find the wordsize (32-bit or 64-bit) of Oracle Database

If you have access to an Oracle database which is installed on a 64-bit OS, how can you identify whether Oracle is 32 bit or 64 bit ?

Gary Robinson's oracleadvice.com has very good pointers on how to determine the wordsize on http://www.oracleadvice.com/Tips/32or64bit.htm. ; I have tweaked the query given on oracleadvice.com like this:

select (case length(address)
when 16 then '64-bit Oracle'
when 8 then '32-bit Oracle'
when 32 then '128-bit Oracle'
end) Wordsize
from v$sql
where rownum <2
/

WORDSIZE
--------------
64-bit Oracle