Viewing Dropbox files on your iPad is fine, but what if you need to work on them? You will need an iPad productivity app. While Apple's office productivity tools (Pages, Numbers, Keynote) work pretty well, most people still use Microsoft Office. There are a few mobile Microsoft Office apps, but my favorite is Quickoffice Connect Mobile Suite for the iPad($15).

Quickoffice lets you create (or open), edit and save Excel spreadsheets, Word documents and, as of earlier this month, PowerPoint slides on your iPad. Like most mobile apps, Quickoffice lacks the full functionality of the desktop version of Microsoft Office. But Quickoffice has been closing this gap.

One of the coolest Quickoffice iPad features is its tight integration with Dropbox and other cloud storage service providers.

First, you'll have to set up Dropbox on Quickoffice. Launch the Quickoffice app, tap the Edit button, select Add Account, and choose Dropbox. Then enter your Dropbox account information. Now you'll be able to access Dropbox files directly from the Quickoffice app, edit the files using Quickoffice tools, and then save them in Dropbox in the Quickoffice app.