More great ideas from edutopia.org.
http://www.edutopia.org/blog/bell-ringer-exercises-todd-finley#comment-138351
Other Ideas for Bell Ringers–
Photographs- my board from Pinterest http://www.pinterest.com/swilliams2007/pictures-for-writing-prompts/
Izzit.org–Daily articles with comprehension questions. Remember to preview the articles.
The Daily Post-A Prompt a Day Not all are school appropriate; however, many great ideas.