Yes, we have our own mostly because it took so darn long for our school to update our information (disclaimer - I own a company that builds PTO websites). The other posters are correct, they key is to keep the information fresh. I'd recommend that whatever solution you use, make sure multiple people can contribute to it if desired and that it is easy enough to pass on to the next volunteer once you are done. Otherwise, the next person who comes along will try to reinvent the wheel - regardless of how many tireless hours it took you to build it. I hope that helps.
We have a section on the school's web site, but we found that's not particularly effective. Facebook seems to work better, but you have to have the parents "like" your page. With a web site, you have to provide new information on a regular basis, or else people get out of the habit of checking. With Facebook, your new post can appear on their "wall" even if it's been a couple weeks since your last event.
I havn't done this for PTO management, but if I did, I would recommend using Joomla. It's an open source platform that is very robust and dynamic. Basically anything you want to do you can do using a wysiwyg editor (what you see is what you get)
For example, you can have message boards, calendars, user protected pages, forms and file downloads all for free. All it take is a web host, domain and a little desire to learn a new software. Not coding, learning a software like excel of photoshop.
The website is www.joomla.org/ . Feel free to message me if you have any questions about it, I'm always willing to help out a good cause when I can.
I am considering creating a website for the PTO (population ME). I have difficulty reaching parents via Facebook. Has anyone else decided to do this on their own? Does the PTO pay the hosting fees?