It is very easy to add an icon showing your online status (on yahoo messenger and AIM) to your email signatures and blogs.
Edit your email signature and modify the content as follows(Make sure to use HTML view):
<font face=Tahoma size=2>
Consultant (.NET Technologies)<BR>
yahoo id: your yahoo id
<img border=0 src="http://opi.yahoo.com/online?u=[your_yahoo_id]&m=g&t=0"></a><BR>
If you sent an email using this signature you should see something like this. To the right is small icon that shows your online status .
The lines to watch out are:
<a hrefhttp://edit.yahoo.com/config/send_webmesg?.target=[your_yahoo_id]&.src=pg >
<img border=0 src="http://opi.yahoo.com/online?u=[ your_yahoo_id]&m=g&t=0"></a>
Look at the ‘src’ attribute closely . In place of 0 , if we pass other values we get different images.
AIM users can use this technique to display if they are online or not:
border = 0 >
But the disadvantage here is that you can't click on the image and send a message to user. AOL seems to have a nice API for doing what we want here http://developer.aim.com/faq.jsp#presence
I tried doing same with Microsoft Outlook signatures , but it doesn't work. Outlook seems to be replacing the URL with copy of image from its cache. I am looking for a workaround to accomplish it.
Note : Many email clients/services dont show images by default.You may have to click on 'download images' or 'show images' hyperlink.