Notes app keyboard spawning iPhone

Simple question. What is the trick to bring up the keyboard when using the notes app the comes w/ the iPhone? I have the 3G, so I dont know if its different w/ the 4 or the 3GS.
I go into an existing note and want to insert some text in the middle of a note. I try tapping, double tapping, tap move all kinds of things. It eventually comes up after messing with it, but I cant figure out what im doing to make it spawn.
What is the action to bring up the keyboard? Its kinda frustrating.
Thank you.
-CB
3G iOS 4