Dropped a package or overwrote one with old code? Flashback can help...if you need get your DBA to grant the following if they can to you:
grant flashback on sys.all_source to YOUR_SCHEMA;
Now execute this sql to get the package back:
as of timestamp
to_timestamp('04-SEP-2012 10:30:00', 'DD-MON-YYYY HH24:MI:SS')
where name = 'YOUR_PACKAGE_NAME'
can save your bacon....