How to Limit User Blog Posts by Word Count or Number of Characters?

HI Guys,

I posted this at the end of another thread, and was asked to start a new thread, so please forgive if you's already read this.

Is there an existing way or easy solution to be able to limit the size of users posts? Typical application might be a writing contest or assignment strictly limited to 700 words, or forcing a headline to be 100 characters to fit in a defined space.

Also, I'm new here and want to say that I'm really impressed by your guys' willingness to help problem solve.