Okay, so you want a trampoline, and can't get one, because your parents are in fear of paralyzing or killing yourself, right? You can do a few things, and then you will probably have a good 85 percent chance of getting a trampoline.
step 1. offer getting the safety net, it might be the only way.
step 2. if that doesnt work, print some info from this link. www.jumpsport.com/safety.htm
step 3. if that doesnt work, write a fake paper about how only 3 people have died on trampolines, or only 20 people have paralyzed themselves and they were drunk.
step 4. if that doesnt work, attach some info from this link to a box of chocolates and give it to your mom. www.springfreetrampoline.com (this will most likely work)
step 5: if that doesnt work, tell them that u will bounce one at a time under supervision, or that u will get a smaller one that u cant do flips on.
step 6. if all of that doesnt work, which it probably will, show your parents this link to piss them off becuz u know ur not gonna get anywhere. www.video.google.com/videoplay?docid=-3868751167005642764&q=logan
good luck and post if u get one or not!! :)