I've been looking for a trailer to pull my two boys (4 and 3), but it's tough to find one on craigslist for under $100 lately. Yesterday, my neighbor had this out at the end of their driveway with a nice "free" sign. Checked with them to make sure it was free, and with their assent grabbed it!
Took them for a ride around the block (1.3 miles), they enjoyed it. It was a bit like riding uphill the whole way, but it was do-able.