It's in AutoCAD Mechanical, it's in most other 3D modeling programs...so why isn't it in Inventor? Why do packages of hot dogs come in 10 and buns in 8? It's one of the great mysteries of the Inventor user base. Well Inventor user Brian Hall finally got tired of not getting an answer from Autodesk on this one. Not the hot dogs, the rectangle one.
Download Qube-It Rectangle Tools R2
This add-in works beautifully on Inventor 2010 and 2011 assuming you have all the service packs and microsoft hotfixes installed including .NET updates. I find myself using this tool quite a bit and every time I show sketching now in Inventor, I get asked what it is and where do I get it. Here is a video from the programmer himself. Enjoy! Now to work on that pesky hot dog conundrum.