Write notes on your cellphone as text messages

I had an idea a few days ago. It's a variation of the email important to-do items to yourself. If you're out and about, you probably don't have a pen and paper, but you do have your cellphone. You can text message yourself and save it as a draft. (Hopefully, you remember to look at the draft later.) If you don't mind spending a few cents or if the content of the message is important, you can actually send the text message to yourself.

Maybe this idea will become anachronistic when cellphone manufacturers decide to put more PDA functions in their phones...