Extract the Atmega and use it in your own PCB

Hi;
I am developing an speedometer. I have already done all the programation and it works good. Now I am thinking to extract the Atmega and use it in my own PCB.
Is there any project that have used already used this method - programming the Arduino and later extracting the Atmega-?
I would use my own PCB because it will be more lightness and smaller.
Thanks in advance
Anton

The keyword is "standalone". This will get you started...

https://www.google.com/search?q=arduino+standalone