You could alternatively use an online markdown editor (such as http://markdown.pioul.fr/). It'll wrap your paragraphs in <p> tags.
Additionally, since it uses the Markdown syntax, it might give you more than paragraphs if you use more than line breaks. (Have a look at the quick reference for more about the syntax.)
Edit: Didn't see your answer to @kybernetikos. I still think this could help you out. Also note that in HTML (what you'll get by adding <p> tags to your text), whitespace is collapsed (except inside <pre> tags)
Additionally, since it uses the Markdown syntax, it might give you more than paragraphs if you use more than line breaks. (Have a look at the quick reference for more about the syntax.)
Edit: Didn't see your answer to @kybernetikos. I still think this could help you out. Also note that in HTML (what you'll get by adding <p> tags to your text), whitespace is collapsed (except inside <pre> tags)