The internet has an incredible amount of ideas for the Harry Potter party, however, this site provided much of the information for the birtday for my daughter turning 7.  Please be aware this was a 2-3 hour party.  As the children came in I had them do the sorting hat game from warnerbrothers.com and had stickers I printed from the net as house badges.  My older daughter had to take over so I could welcome the other guests in the door.  I was dressed up in my father's renaissance faire cloak and hat and said I was Professor Sprout. Welcome to Hogwart's school of Witchcraft and Wizardry - Extension Program.  The decor was very limited but the kids didn't seem to notice at all (possibly because the Harry Potter game on the game cube in the living room had about 7 of the chidren entranced). We had a jump outside that kept some kids happy (my neighbors graciously volunteered to watch them). I had to finish the hats (letting them do it took too long) made out of black wrapping paper (the kind in the party store for over the hill parties; I didn't want to use newspaper because the ink would get everywhere) shaped into cones and excess cut off and rolled up on the bottom. After welcoming all the children, letting them decorate their hats with stickers, jump in the astrojump outside and wilting from the heat, I changed into regular clothes and served the birthday cake (all the while my husband had been preparing hamburgers and hotdogs outside) just in time for the first batch of kids who had to leave at 2:00 were heading out the door. I then got back into my costume and started classes. I gave out harry poter wand candy dispensers but I don't suggest it because they will open them and eat them ignoring the whole class presentation.  Let's not forget this was a group of 6-7 year olds.  The classes were potions (7 up and pop rocks; vinegar and baking soda), transfiguration (flubber), and herbology.  My husband had the idea of putting sand into dixie cups and give them dried beans to plant.  Then I took the tray of "plants" to the "greenhouse" (garage) and dumped out the sand and beans and replaced them with the Harry Potter Mandrake dipping sticks (little pots with dirt colored sugar with a sprout that is attached to a candy mandrake that the kids lick and dip into the sugar). I came back and told them how well their plants had grown. At this point I suggest you make them put them into whatever goody bag they have because the will open them and start to eat. By this time it was time to go.  There were 19 children all together, 8 adults (thank goodness).  I had made broomstick pencils and laminated bookmarks from the warnerbrothers website for their goody bags, in addition to chocolate frogs (another new HP candy), chocolate coins, plus the regular blow streamers and Harry Potter glasses from the party store.  I put them into a regular brown paper bag with the top edges rolled down and put a sticker with the Hogwart's emblem on them. These turned out better than expected because they looked like old time candy bags! Thank you to all of the people who submitted ideas to this website where I could create such a wonderful party. My neighbors said they have been to theme parties before but never one this great.  They especially liked the wizard hats. As a thank you for watching the kids in the balloon jump, I gave them treats I found also on the web: wizard wands (melted chocolate frosting dipped pretzel rods rolled in chocolate sprinkles and kept refrigerated) and cockroaches (although my husband said they looked more like chocolate slugs). These were rice krispies shaped like cockroaches dipped in melted candy drop chocolates used for making home made candy -- make sure you read the candy directions or you'll ruin the batch. I hope your party was as fun as ours!