This week, I had an acquaintance ask me to build a web front end to a ruby gem he had someone else build and he complained when I told him it would take more than one day.
I'm curious what other worst client requests have been and what your responses are...
Those sites set up unrealistic expectations for services from a professional that needs years of knowledge to ply their trade. I call them the project lottery some times someone gets lucky and gets a good developer who is just starting out. The rest pay for it in failed projects that no developer will touch without an agreement to abandon any code already written.
If twitter could be written for $500, the world would most certainly be a different place. Alas it is true, there is a sucker born every minute.
You might be interested in this site: http://clientsfromhell.net/ particularly the Twitter one.