iRentMovie is an app for the iPhone that you can download from the App Store. It allows you to do the basics with your queue, plus search for movies in a specific range of years or narrow your searches to Blu-Ray only movies.
You can also do limited management of your queue with Twitter. Complete instructions are here, but the gist of it is, you link your Twitter account to your Netflix account and follow the Twitter profile addnetflix. Now you just add movies to your queue by sending a direct message (DM) to addnetflix. For example, d addnetflix Terminator Salvation will put the movie Terminator Salvation in your Saved queue. Addnetflix will direct message you back with its actions. If it got the wrong movie or you change your mind, you can send an undo command to undo your last DM. There are also instructions for adding currently released DVDs to specific places on your queue, otherwise, they go to the bottom.
There are several other apps there for mobile phones, all of which seem to be free. If you don't see one for your platform, you can always use the Netflix mobile web page which is a lightweight page designed for mobile browsers. Until the WinMo app came out, this is what I used and it allows you to do basic queue triage while on the go. You can add movies and send a movie to the top of the queue, but you can't do any other queue reordering. I still keep this link handy because it's search tool does allow you to search by actor.