Whenever you see a list of information, whether in a report or a task list, you'll notice that there's an Export drop down in the upper-right corner of the page.
Export to Excel will create an .xls file which has formatted the data into a more readable format, however, some older versions of Excel may not be able to read the formatting.
Export to Excel Unformatted will create an .xls file which is unformatted and is more readable for older versions of Excel.
Export to MS Project will create an .mpp file for importing into MS Project.
Export to MS Project XML will create an XML file of the data for importing to MS Project.
An export dialog window like the following will appear following your selection.
Click Open with to open the file inside your copy of either Excel or Project. You can also chose to save the file to open later or for use as an attachment.