On NetTuts there's a new tutorial showing how to take data from a MySQL database and translate it into a usable Excel file with the help of some simple PHP.

A CSV (Comma Separated Value) file is usually sufficient for exporting MySQL data as an Excel Spreadsheet. These CSV files are data only though. A real Excel spreadsheet has formatting, formulas and perhaps even graphics - the difference between a simple method of data transfer and a professional report. This tutorial shows how to use open source PHP components to create "real" Excel spreadsheets from MySQL SELECT statements.

With the help of the PHPExcel tool, making Excel-formatted files is a simple process. They show how to label columns, pull data out with a "quick and dirty" SQL statement, formatting the results to something a bit more clean and iterate through the pages of data to push them into the spreadsheet (including formulas). You can download the full source to get everything in one shot.