Add Email Button In Chrome To Send Link Using Gmail

Rightclick the Bookmarks Bar and Add page... If the Bookmarks Bar is not visible press Ctrl + Shift + B
For Name choose e.g. Send Link.
For URL fill in the following :
javascript:window.open('http://mail.google.com/mail/?ui=1&view=cm&fs=1&tf=1&to=&su='+encodeURIComponent(document.title)+'&body='+encodeURIComponent(document.location),'addwindow','status=no,toolbar=no,width=575,height=545,resizable=yes')

This will open a Compose window in Gmail using the page title as the subject and link address as the message.