You know, before I got the phone, that question never entered my mind. I kinda assumed that it was a standard (me being jaded with my iPod touch). But, it kinda doesn't make sense that there would not be a stock note taking application. At least a very basic one.
So, well, to answer your question, no, there isn't a notepad app. But to be honest, I would likely ditch the preinstalled one for an app called
Evernote. Coupled with the desktop client, you can automatically sync notes onto your computer. Rather than emailing it to yourself.It can also do audio and pictures as well. You can see what you get for the free version
here. I have been perfectly happy with not having their Premium service.