Really? If you're on the latest iOS (v4.3.5) your iPad is capable of multitasking. To switch between programs just press the home button (circular button on the face of the iPad once) and you'll be returned to the home screen. Tap another program and it will open. Double press the home button again and the screen will slide up to reveal all of the running programs. Tap on any of them and that program will slide into place in the state you left it.
So you can have an open email, go and copy the copyright symbol and then move back to your email and paste it in.
If that doesn't work, detail exactly what you're doing and we'll work through it.
Hope that helps!
Here's an article showing all of the existing symbols that are available on the iPad:
Keyboard Shortcuts and Typing Tips for your iPad, iPhone or iPod Touch
FWIW for folks that use a lot of symbols there's an app called "Cymbol" that has all sorts of options (it's an iPhone app but I believe it will work on the iPad although I haven't tried it):
Cymbol for iPad on the iTunes App Store