emotion icons for Gmail
1.install
Grease Monkey (script manager)
2.register userscripts.org
3.login to userscripts and install this (.js) script to browser.
Gmail Emoticons ! Userscripts.org
4.and then.,login Gmail.
5.you will get the emotion icons at your Gmail as show in figure.

very easy ways to using...
*Click on the Emoticons button next to Check Spelling in the Compose Window in Gmail.
*DRAG your mouse cursor over the Emoticon image to HIGHLIGHT it (as you would highlight/select text).
*Once the image is darkened (selected), right-click & press COPY (NOT "Copy Image" & NOT "Copy Image Location"!!)
*Go back to your Gmail compose-mail box and right-click & press Paste.