If you're just printing a username to a file 70 MB sounds *very* excessive. What does the file look like when you are done? It sounds like you're getting dupes or something. Can you post your code? Also, have you looked into the Spreadsheet::WriteExcel modules[1] on CPAN?

~Charlie

[1]http://search.cpan.org/~tmtm/Spreadsheet-WriteExcel-Simple-1.02/Simple.pm[/irl]