Here are some more useful keyboard strokes that work in the new PowerShell ISE script editor that comes with PowerShell v3. These keyboard shortcuts work inside the script editor pane:
CTRL+J: opens code snippet list to quickly insert predefined code blocks
CTRL+M: toggles regions
CTRL+F: finds text in a script
F3: finds next occurrence
SHIFT+F3: finds previous occurrence
CTRL+H: replaces text
CTRL+G: go to line
CTRL+U: to lowercase
CTRL+SHIFT+U: to uppercase
CTRL+SPACE: start IntelliSense
CTRL+1, CTRL+2, CTRL+3: changes position of script pane