SET NEWPAGE 0
SET SPACE 0
SET LINESIZE 80
SET PAGESIZE 0
SET ECHO OFF
SET FEEDBACK OFF
SET HEADING OFF
SET MARKUP HTML OFF
SET ESCAPE \
To Drop all your tables you can use the following in a script:
SPOOL DELETEME.SQL
select 'drop table ', table_name, 'cascade constraints \;' from user_tables;
SPOOL OFF
@DELETEME