Hi,
for that purpose I use following script. It's not perfect but works ...
Code:
clear breaks
column logon format a22
column sid format 999
column machine format a15
column program format a25
set pagesize 200
set linesize 110
select sid, serial#, machine, program,
       to_char(logon_time,'yyyy.mm.dd hh24:mi:ss') logon,
       status, first_load_time, sql_text
  from v$session, v$sql
 where v$sql.address(+)=v$session.sql_address
   and status='ACTIVE'
 order by first_load_time