How do you upload a picture onto craigslist org classified ads?

upload your picture to some free image sites (photobucket, imageshack.us) and then use that URL with the img tag while posting to craigslist

E.g:

http://imageshack.us/123image.gif --- is the URL of my image uploaded to imageshack.us. When i post my article to craigslist i use the img tag as follows

<img src="http://imageshack.us/123image.gif" alt=image" title="image"

I just use listhd.com to create an image gallery.