At first glance, you might consider Docs to Go for iPad to be an expensive app if they're expecting you to pay more than $10 for it (the actual price is $16.99). After all, it does basically just what a program like Microsoft Word does, only portable. Why should you pay $17 for something that comes for free with your computer?
Probably because it didn't come for free.
You may not have noticed, but there was a $150 price tag that came with programs like Word, Excel, and Powerpoint, and it's all hidden in the cost of your computer. Docs to Go for iPad is incredibly cheap in comparison, and is arguably the most versatile of all the versions (iPhone, iPad, iPod, etc) simply because it's the only one with a full size display that you can legitimately type on without too much trouble. Oh, and it also doesn't just view .docs; it handles Excel files and Powerpoints as well, meaning you have a three-in-one application that Microsoft is selling for $150 for just $17. Doesn't sound so bad anymore, does it?
In addition to being able to view all of these file types, you can also create your own from scratch directly on the iPad's user interface.