As with word processors, you do have options beyond those in Office 2008 and iWork ’08.
Say you want to run Excel macros, which the 2008 version of the product can’t do. Right now, your best option is to stick with Excel 2004.
NeoOffice (free), a port of OpenOffice that runs natively in OS X, supports Excel 2004’s macros, at least to some degree. (Some of my macros worked perfectly; others didn’t.) It can also open Excel 2008’s and the Windows-only Excel 2007’s new .xlsx file format, and it offers excellent compatibility with Excel functions.
OpenOffice (free) is also developing a native OS X port, but it’s a work in progress; you may experience some compatibility issues. Like NeoOffice, it’s compatible with Excel functions, but it doesn’t properly handle the new Office 2007 and 2008 file formats.
If you’re willing to pay, Mariner Calc ( ) can handle most basic to intermediate needs, though it can’t import all Excel worksheets and doesn’t offer full formula compatibility.
[Rob Griffiths is a senior editor at Macworld.]