You can view an iWork ’09 document on your iPhone (or iPod touch) in the Mail app, if the document is received as an e-mail attachment. You may also view such files on your iPhone using third-party apps, such as FileMagnet. Unfortunately, as reported by Apple, these iWork ’09 documents may not display correctly on the iPhone. When using Mail, they can even cause the app to crash.
When I tested this out, a Pages ’09 document showed up as blank in Mail (although it did not crash the app). When I tried to view the same file via FileMagnet, the file refused to open, stalling with a spinning sundial icon until I force-quit the app.
The recommended work-around is to convert the iWork ’09 document on your Mac either to an iWork ’08 document (using Pages’ Save As -> Save Copy As command) or to a PDF (using the Save As PDF option in the Print dialog). Send one of these alternate versions to your iPhone and it should display correctly, with no crashes. I tested out both work-arounds, in e-mail and with FileMagnet, and indeed had no problems.
Expect Apple to fix this bug in a future update.