Microsoft Office 2007 was first released for PC users in late 2006 — introducing a slew of new file formats that couldn’t be opened on a Mac. These new formats include Word 2007 documents (docx), Excel 2007 spreadsheets (xlsx), and PowerPoint 2007 presentations (pptx). The new Mac Office 2008 isn’t expected to ship until January ’08.

We field calls every month from Mac-based design firms who find themselves receiving these new Office 2007 file formats from their PC-based clients. We wrote a tip back in February 2007 called Convert MS Word 2007 .DOCX files for a Mac, but that only covered one of the new formats.

The good news: Apple’s new iWork ’08 which shipped in August can open and save in all those new formats. So if you are a designer who often receives files from PC-based clients, buying this new $80 package can greatly simplify your life.

Word 2007 Documents (.docx) can be opened on the Mac in Pages ’08

Excel 2007 Workbooks (.xlsx) can be opened on the Mac in Numbers ’08

PowerPoint 2007 Presentations (.pptx) can be opened on the Mac in Keynote ’08

Source: This tip inspired most recently by a phone support conversation with Gravity Design.