You can now compare tables online on the COOPY website. Compare CSV files, Excel spreadsheets, Access and Sqlite tables. MySQL tables can be compared by the downloadable tool, but not from the website, which is restricted for security reasons to comparing files.
One use for this service is as follows. Suppose you're working with public data, and have made some improvements to it (fixed typos etc). You'd like to send those changes "upstream" to the source of the data. If you compare the original data and your version with COOPY's table comparison utility, then a page is created for you presenting the differences in a clear way, along with an easy way to apply those differences. Pointing "upstream" to that is more likely to get a better welcome than emailing a big blob of who-knows-what in a format the data may not be maintained in.
