The Inventor 2012 release introduced a new way to experience the right click interface we have been so accustomed to over the years. This new way of viewing the RMB (right click button) is known as the Marking Menu.
It was developed with many studies in psychology, learning behavior, and visual awareness. These results of these studies state that users new to computers or drafting software seem to realize options in a radial pattern easier than a linear direction. All of which I couldn't care less about since I have been using computers for a long time and Inventor since release 4.
While a very neat addition to the software, I found at first the radial menu very irritating much like the initial change to the Ribbon in Inventor 2010, but over time using it (after about a week for me) I grew very fond of it and actually started to see my speed increase in the software over the previous menu after acclamation to it. But I also felt the need to customize it based on my usage of Inventor. To that end, there are actually quite a few little items to change in the marking menu to better suit the commands you want to see there and how you want to see them. Not to mention, you can also utilize mouse gestures with this new interface style.
First go the Customize command.

On the marking menu tab (third one over), you will find the settings for the interface. To change the items in the radial menu, simply select the location first to modify and then find the command on the right command list. The selection of an item on the right will automatically relink to the location selected.

You can also change the marking menu style to show only Text or Icons...

If you prefer the original RMB you can also set the check mark box for "Use Classic Context Menu"
Now if you are curious what I meant about mouse gestures, that does not relate to Mickey Mouse giving you the hang loose, heavy metal, or other hand gestured sign, but instead refers to the quick movement of the mouse in a general direction to start a command. In Inventor, you simply have to know where in the marking menu your command is located and then with a flick of the mouse perform a right click and a drag in the that direction and release of the right click.

Gestures and the marking menu have really sped me up with the software. Sure we are talking seconds every hour and minutes every day, but in the end I am getting my work done faster and with less hunting for commands I use all the time. In fact I find with the newer 2012 interface in general I am starting to forget all about my complaints with the Ribbon since more of my work is in canvas now. Whatever way you decide to use the new interface, just at least give it a chance.