Flix [App Store] is a $1.99 application that allows you to manage your Netflix queues. The developer describes the app:
Add, remove, and reorder movies with a few easy flicks of a finger. You can rate movies youve seen recently, see ratings and descriptions for all the Netflix top lists, and even search for a particular title to learn more about it before popping it up to the top of your queue.
Also provided is an extensive tutorial with screenshots on how to accomplish various tasks on the iPhone.
View your shipped, queued, and saved movies at a glance, including cover art
Drag and Drop Queue Reordering
Swipe to Delete Movie removal
View movie details quickly and easily; Stars, Director, Description and Cover Art
Quickly add movies from popular RSS feeds
Search for and add movies on the go
The developer does offer a free version called Dashbuster Free [App Store] which does not allow you to add or change movies from your iPhone, and will incorporate ads in the future.