As there is no form for easily generating the proper image url, we must construct one by hand.
To do so is simple:
http://www.EchidnaTribe.org/error?n=I+am+errorReplace the bold "I+am+error" with your own message, using either "+" or "%20" for spaces. The "&=.jpg" at the end is optional, and merely serves to keep simpler/older browsers from becoming confused as to how to display the image.
The trailing punctuation will be added if one is not included. Line wrapping is automatic and currently limited to 4 lines, even though only 3 lines would be "natural".
Then, if you are happy with the result, you may use the [ img ] or [ url ] tag to link to it here or elsewhere. (Maybe I'll regret saying that...)
You may also use the url
http://www.EchidnaTribe.org/error to get a random message every refresh, as well as
http://www.EchidnaTribe.org/error?r=0 (where "0" is any positive whole number or 0) to see specific messages from the random selection. There are currently 35 messages total. (That is,
34 is the last one)