AutoText - EmotiKons
This extension provides the EmotiKons icon set (taken from kdelook.org) as autotext in OpenOffice.org Writer.
After installing the extension type :) followed by (F3) and you will get a smiley picture.
Unfortunately not all shortcuts are detected by OpenOffice.org. In such a case you need to select the emoticon characters first and then press (F3). Or enable the Insert toolbar (View - Toolbars - Insert) and choos your EmotiKon using the Insert AutoText icon.