Yet another viper

In Linux/Unix world two editors are raging war on each other. Some say emacs is the best editor and others say vi is the best editor. Google for "vi+emacs", you will see tons of blogs posted, supported there own favored editor. I, on the other side don't support either of them, and yes, I have used both of them. I feel both of these editors have there own advantages and disadvantages. So, for some time I have been searching for a editor which supports switching between these two editor modes dynamically. 'Viper' is one such package which can be used to emulate 'vi' like functionality within emacs. You can also use emacs commands in insert mode if you know any. I think there is a similar add-on available for 'vi' also. If I find one I will get it posted here, for your and my reference.