Search for highlighted text with *

In your .vimrc

Add these key maps to your .vimrc:

vmap * y/<c-r>"<cr>
vmap # y?<c-r>"<cr>

How to use it

• Select some text in visual mode.
  
• Hit *, to find the next occurance.
  
• Hit # to find the previous one.

How it works

y/<c-r>"<cr> does the following:

• y yanks the currently highlighted text to the default register which is ".
• / begins a search
• <c-r> allows you to insert the contents of a register. In this case we are insert the contents of the unamed registers ". This is very powerful and you can use this in a search or on the vim commandline.
  
• <cr> carriage return -- same as hitting enter.

I got this trick out of the vim docs