I think Nadine is on the money. I would add that you should have a craft that is part of the theme as well. Use your creativity when programming. Let's take a look at a couple of the themes you have.
Magical Mayhem - This could include the kids learning magic tricks. Many tricks are very simple. Visit a magic store and they will be happy to help out. Have a the kids throw cards into a hat placed 5 feet away as a competition. Show one of the Harry Potter movies. Make paper wands. Etc.
Nature Nuts - Have some animals brought in petting zoo style or have an animal trainer visit. You'll be amazed at how many people will volunteer their time for kids. Have them grow plants in paper cups that they decorate. Again, the library will have a lot of good books for kids activities, especially nature related. There are lots of great Disney movies with animals. Use the week to teach about the environment.
Hollywood Bound - Karaoke, drama games, skits, Hollywood decorations, etc.
Other suggestions for themes: Nickelodeon, Under the Sea, Wild West, Holidays, Superheroes, Olympics, Dinosaurs...
Well, you get the idea. Break each day into two parts separated by lunch. Have a morning activity and afternoon activity. Keep in mind that not every activity needs to be part of the theme. You may also want to talk with someone from your local parks and rec department that puts on day camps. Even though you are "competition" I have found that recreation people are happy to share ideas. Get a daily schedule from them, or create your own. A daily schedule is really where you want to start.
There are a lot of factors in what you do and how you do it including the ages of your campers, the number of campers, your budget and the amount of staff you have.
One last thing, Nadine offered some good websites. I would like to add
www.recreationpros.com It's a new site with some neat program ideas. The guys who run it are very nice. Email them and they will certainly help you out with any programming challenges you might have.
And did I mention that you should visit your local library? Good Luck!
