How do you create your signatures? First, get yourself a copy of the facebook icon, ideally as a png file. I'd suggest you use Thunderbird. Start a new HTML message. Clear everything. Add your text. and use the Insert menu to insert an image, using your image of the facebook icon. Tick the checkbox to attach the file. Select the Link tab and enter the URL you want the picture to link to when clicked on. Note that your link won't work in Thunderbird's editor window. You'll need to save it as a draft and view it there to check that it appears and works as required. Save your message as an HTML file (File|Save As). Finally, go to your account settings and nominate your HTML file to be used for the signature. Tick the box labelled "Attach the signature from a file…" and browse to your HTML file.