While typing using the Notes application on your iPhone (or jailbroken iPod Touch) sometimes you want to go back and change or correct something. But it can be tricky to ‘tap’ exactly where you want the cursor to go. Here’s a neat trick I just discovered today – tap in the general area you want to put the cursor, and hold your finger down. A magnified view will appear, and you can “drag” the cursor exactly where you want it.
Update: as reader Philip points out, this actually works in all iPhone/iPod Touch apps (other than some 3rd party programs like Term-vt100).