I love it when I come across a new thing on the iPad that I did not know. I was reading a tip’s and tricks blog post on the ipad and I learned about how to pause an app from being installed.
http://www.howtogeek.com/howto/14529/the-complete-list-of-ipad-tips-tricks-and-tutorials/
You basically hit the icon of the app that is in the (waiting or loading) state and it will turn to paused. What a great feature when you start to update all apps and then want to surf the web or get a large attachment