Excel enables you to turn data into information with powerful tools to analyze, communicate, and
share results. Excel can help you work better in teams, and help protect and control access to your
work. In addition, you can work with industry-standard Extensible Markup Language (XML) data to make
it easier to connect to business processes.
Though almost all my soft is portable/freeware, Excel is an exception - so far it's just the best
spreadsheet program. Other spreadsheet programs (OpenOffice Calc, Gnumeric, Spread32 etc.) are good
but still far down Excel.