Muthu Kumar Arjunan has posted the second article in his series on XSL transformation of SpreadsheetML data over on OpenXmlDeveloper.org. This article looks at how to generated a paginated set of documents (HTML pages) from a large spreadsheet, using XSLT. Here are links to the two articles:

XSL transformation of SpreadsheetML to HTML -- Part 1
XSL transformation of Spreadsheet ML to HTML (with Paging) – Part 2

If you're implementing Open XML solutions in a heterogenuous environment with non-Windows systems involved, the ability to display a SpreadsheetML document in a browser will be very useful. Muthu didn't use the packaging API in his example, so that you can easily port his sample solution to the development environment of your choice.