Of the many new features in iOS 5, some of the most subtle changes came with the Mail app. iCloud now brings a free email account to anyone who wants to snag one, and that email account is accessible from any device -- Apple or not.
First, text can now be formatted using bold, italic, or underlined. To apply formatting to a word or paragraph, select it using a double-tap, and use the handles to extend or shorten the selection if needed. The standard cut/copy/paste/suggest... menu will be floating over the word, with an arrow pointing to the right. Tap on that arrow, and it reveals a second menu displaying BIU for bold, italic, and underlined. A tap on BIU brings up the individual buttons for Bold, Italics, and Underline.
Next, you can now create indents in your message -- actually what you're doing is changing the quote level. To do this, tap any place in a line to display the select/select all/paste menu. Once again, there will be an arrow pointing to the right. Tap the arrow to reveal a button that says Quote Level. Tap once again to show two buttons, Decrease and Increase, which allow you to increase or decrease the quote level of a specific paragraph.