I just discovered the blog of the lovely Madeleine Kane, who creates a Limerick challenge every Monday for open participation.View details via link above. Basically, she writes the first line of a Limerick and anyone is free to submit their own continuation of the verse.
This week's opening line was: "A man who was known for his flash". I highly recommend clicking over to her blog and reading some of the highly entertaining entries!
A man who was known for his flash
was too quick for the coppers to stash;
garbed only in skin,
his big, toothy grin,
and below a revolting mustache.