The import and export of data in is key for most successful applications. Here are some ideas:

• export a map as SVG or PDF (any others?)
• import and export data via CSV from or to other applications like e.g. Thunderbird or Outlook for PIM or Calc or Excel for spreadsheets
• import and export VCARD for contacts (PIM)
• import and export ICAL for calendar (PIM)
• import and export all / a selected / filtered set of data in XML and RDF