I Need Some Demonstration Speech Topics. Does Anyone Have Any Ideas?

Teach them to linedance while explaining the steps and benefits for dancing.

How about  a camera, a digital or a polaroid, where they can see the result. Or your cell phone and its special feature. You could do one on using the phone book, lot's of people do not know how. Show them a thesaurus, lot's of people do not know how to use them. If you have a special skill like music, demonstrate the basics of that, musical instruments usually go over well. If you haven't found something in a day or so , let me know . We will do some brainstorming! O.K. Good luck!  *p
ps, if you play sports you might want to talk about the rules and basics of the game you play.

If you really want to score points and grab your audience's attention, then a great demonstration speech should involve getting the audience INVOLVED;
some examples are: Dance (teaching a short dance routine; actually getting the audience out of their seats for a few moments...or ie. A cooking demonstration using ingredients that do NOT have to be cooked: One I used No-Bake Oatmeal Cookies: Ready in: < 30 minutes
recipe difficulty 3/5 Difficulty:   3 (1=easiest :: Hardest=5)

Serves/Makes:   3 dozen
  

Ingredients:
2 cups sugar
3/4 cup butter
2/3 cup milk
1 (4 serving size) box instant pudding, any flavor
3 1/2 cups quick cooking oats
1/2 teaspoon vanilla extract
Turn this recipe into a puzzle! [click]

Directions:

Mix together the sugar, butter or margarine and the milk in a lg. Pot and bring to a boil. Boil for 2 minutes. Turn off heat and add in the pudding, oats and vanilla. Mix well and let stand for 5 minutes. Drop by spoonfuls onto waxed paper.

This recipe from CDKitchen for Easy No Bake Cookies serves/makes 3 dozen

Just two ideas. If you can't dance and don't like cooking (remember the greatest chefs are MALES) then just find a topic that gets the audience involved. One last clue: To lighten up the air in the room (make people smile) add some humor to your speech. Find some "tasteful jokes" that do NOT involve sex, religion or slang politics. You can google.com and type in: Non-offensive jokes...to get some ideas.
So, my friend, 3 things to a great speech:
1. Keep it relatively short but active
2. Get the audience' attention with humor, exercise or FOOD
3. Thank the audience for their time and smile at the end.
Good luck.

Maybe knitting but i dont think food is a very good idea because a lot of people are going to do that or you could do how to draw ....