Google has a Docs viewer web app for iPhone that will let you view all your Google documents. However, this application does not actually let you create or edit documents on the go. iGoogDocs is an iPhone app that will make it possible. The application is not just built for Google Docs, but for accessing over 20 of Google’s products including Gmail, YouTube, Picasa, News, Reader, Earth,etc.
With respect to Google Docs, the application will let you to create a new document, edit existing documents, save documents as a local file, as an attachment on email, defer it for a later upload or upload the changes directly to your Google account. The application also lets you translate your document to over 13 different languages.
iGoogDocs is available on the App Store at a price of $1.99. If you are looking for a free non-editing version of Google Docs, you can check out Memeo Connect. Got to know that the Docs editing feature is coming soon there as well.