Essay topics

My composition teacher never gives us exact topics for our essays, he just says: "write a cause/effect essay", "definition essay"....

i think this "freedom of choice" is worse than when you have an exact topic to write about, because i always spend a couple of hours just deciding on the topic.

if anyone has any ideas on where to find possible college essay topics, or if you have suggestions for my upcoming essay on cause/effect (4-6 pages, double-spaced), please HELP!!

thanks in advance

desperate college sophomore