run on sentence exercises

http://www.kishwaukeecollege.edu/learning_skills_center/online_writing_center/run-on_sentences.shtml

http://www.localschooldirectory.com/lesson-plans/id/464

http://mrshatzi.com/files/run-ons-ws-1.pdf -- this one specifically targets the connecting words then, therefore, and pronouns such as "it" and "they." Students create sentences.
http://mrshatzi.com/files/run-ons-ws-2.pdf

This one is lots harder - students have to sort the run-ons from the legal sentences (such as ones with comma and "but" or a semicolon). The teacher has lots of other worksheets online.

Another already-a-word-document worksheet with examples of spliced sentences is here.

This one I rather like 'cause of its nice layout - a little extra effort makes a big difference. (Okay, and it does what I like to do and takes examples from literature, even if Captain Underpants isn't usually where I go with it...)