Google Refine is a free desktop application designed to clean up messy data or transform it from one format to another.
The program performs "faceted browsing," which functions like pivot tables in spreadsheet programs. Refine also uses clustering to group similar but irregular cell data like names and dates, which can then be corrected.
For advanced users, Refine is capable of reformatting data using Web services (geocoding for example) and using "recipes" for complicated, but common, tasks.
Refine supports the following formats, according to its documentation: