Need help with gymnasium acoustics.

I won't be shy. The Lincoln School PTO in Pontiac, Illinois could use a handout in the form of an acoustic engineers opinion/ advice. The gymnasium/ lunch room is a major echo chamber.
At lunch time, the employees have to keep telling the kids to be quiet as the levels reach a painful roar. At PTO meetings, it's impossible to hear what the speaker is saying through the microphone. I went to measure/ look at the room with the principle. Our two voices alone were echoing badly.
The room is 68'10" long, 41' wide and 18'6" tall. The stage end has a large heavy curtain which covers most of that end of the room. The long walls and rear wall are smooth painted concrete block. The long walls have multiple windows and doors up to the 8' level. From there up it's solid block. The ceiling is some type of hard smooth surface with steel ceiling joists exposed. Overhead lights drop from the ceiling to a level nearly flush with the bottom of the joists. The floor is smooth tile.
The PTO knows this is a big problem and has been saving money to try and remedy the situation. They have $2500 saved so far. Is there something they could do for that kind of money that could do some good. I suppose the treatment would have to meet fire codes and be able to take basketball hits etc...
Thanks in advance for any opinions. You could help a lot of people who are currently going bonkers. If you need pictures, I can e-mail them.
Thanks again
This approach should make it liveable:

1. get the Home Ec classes to sew colorful fabric banners, use thin polyfill batting on some of them; have staff attach them hanging from the exposed steel ceiling joists via fabric tabs. Alternate a 2 or 3 ft banner with a space so that 50% of the length of each joist is covered.

2. find out whose daddy owns the local Heating/air conditioning contractor. Get them to supply some 4 ft by 8 ft by 1 or 2 inch compressed fiberglass panels at (or near) cost. Have the shop class cut these into 2 ft squares. Cover (Home EC again?) squares with fabric. Attach to the walls, covering 25% to 33% of the area from knee-level to 6-10 ft, depending on how much you can afford.

One of these projects alone won't do the trick, but even a limited amount of coverage of both will help. Your budget should cover if you can get the staff and kids to donate the labor.

Best of luck,
Thanks Joe. Anyone else professional or otherwise is welcome to comment.