Is there a keyboard shortcut in outlook 2007 to flag an email instead of having to mouse click the little flag?
Autohotkey could do it!
What you want to do is install AHK, then use the bundled Window Spy to find out the position of the button. Then you'd use something like this:
#IfWinActive, ahk_class [whatever outlook's class is, the window spy will reveal this] [your hotkey here]::Click, X of flag, Y of flag #IfWinActive
edit: djhowell says you can use Control+Shift+G, then return. In this case your hotkey would be:
Keep it simple!