Fun With Text on Mac OSX

Tech Goes Boom has an article regarding moving around in Bash and Cocoa applications:

Control-A: Go to beginning of line
Control-E: Go to end of line
Control-K: Cut to end of line
Control-Y: Paste what you cut
Control-T: Transpose letters
Control-R: Search history backward. See below for more on this command
Escape-F: Forward one word
Escape-B: Backward one word
Escape-Delete: Delete one word backward
Escape-Control-H: Delete one word forward

So try one of the above when trying to move around on a line of text and don't want to take your hands off the keyboard. Read the article for more details.