You can use the scratch plugin to create a temporary scratch buffer to store 
and edit text that will be discarded when you quit/exit vim. The contents 
of the scratch buffer are not saved/stored in a file. 

Installation 

1. Copy the scratch.vim plugin to the $HOME/.vim/plugin directory. Refer to 
   the following Vim help topics for more information about Vim plugins: 

      :help add-plugin 
      :help add-global-plugin 
      :help runtimepath 

2. Restart Vim. 

Usage 

You can use the following command to open/edit the scratch buffer: 

      :Scratch 

To open the scratch buffer in a new split window, use the following command: 

      :Sscratch 

When you close the scratch buffer window, the buffer will retain the 
contents. You can again edit the scratch buffer by openeing it using one of 
the above commands. There is no need to save the scatch buffer. 

When you quit/exit Vim, the contents of the scratch buffer will be lost. 
You will not be prompted to save the contents of the modified scratch 
buffer. 

You can have only one scratch buffer open in a single Vim instance. If the 
current buffer has unsaved modifications, then the scratch buffer will be 
opened in a new window 
 
install details
1. Copy the scratch.vim plugin to the $HOME/.vim/plugin directory. 
2. Restart Vim