The topic of keyboard shortcuts has proven to be extremely popular. Because of that, I have gone through almost all of the keyboard shortcuts available so that you can see what can be done by holding down various keyboard keys on an iPad. The screen shots below reflect the keys available under iOS 4.2 on a English language iPad.
The following are a few of the extras symbols that are available as shown below: § ¿ ¡ ~ ” ü ¥ •
First, there are three keyboards available on the iPad. They are as follows:
Letters Keyboard
Numbers Keyboard
Characters Keyboard
Next, specific shortcuts are listed below. Make sure you have selected the correct keyboard so the characters you are seeking to insert are available.
§ (lawyers and others made need to use the section symbol)
Single Quotation Mark Variations
.com .edu .us .org .net (Note: additional choices may be available when you attempt to type an email address in Mail)
• – —
%
Various Non English Language Specific Characters
? ¿
¡
Various Letter Variations of – a c e i n o u
If you know of any other short cuts, let me know.
iPad Notebook 
on the numbers keyboard holding down the “0” will give you the symbol for degrees
You can also learn more keyboard shortcuts here and here.
This is great info. My Google search on how to type a section symbol took me to this page. The illustrations are extremely helpful. This is way easier than typing symbols and foreign language characters on my PC laptop and desktop! Thanks, Justin!