As a matter of fact, there are some Middle School parents here. Tell US, what would you like your PTO to do? Consider it a practice run for your own PTO and you'll also help those who have children your age do things within our own groups that they would enjoy.
I agree with AJ. You can talk to your friends parents and they can help you come up with some suggestions that interests your age group and bring it before the PTO. You yourself can talk to the PTO pres and say just what you said here.
When kids get older it gets harder to figure out what interests them and what doesn't. Sometimes we get so caught up in figuring out what needs to be done and not do the simpliest thing...ask the kids.
Chances are, your PTO is made up primarily of parents of younger students. Try asking your parents and the parents of your classmates to get involved in your PTO. Student representatives are involved in some middle school PTOs. Your PTO won't know what type of events interest you without your input. No PTO I know of will turn away ideas and help from anyone eager to be a part of their group.
I'm a student at a school of a range of K - 8. The PTO is only doing events for the younger kids and makes the middle school sit through it! I don't want to sound ungrayeful because i love missing class time but I'M NOT THAT YOUNG.