I just got one of the Corsair K55 keyboards too, mainly because of the Macro keys. I used to love them on the Gateway 2000 computers I used to have, back in their heyday.
The macro keys can do all the things you've listed. It's simple. Just hit the MR button on the keyboard (which you'll find towards the very top of the keyboard, to the right of the "CORSAIR" logo.
After hitting the MR button, you'll see a white light slow-blinking. Then hit the macro key you wish to program (one of the G1 - G6 keys). Then, type anything at all with the keyboard, and when you're done, hit the MR button again to save the macro.
To do something like launch the calculator, you can use the Windows-R key combination (windows key then R) to bring up the launch window, and type the program you wish to launch. This can be the calculator, or iexplore.exe if you want to launch IE, or anything else.
For example, to set the G2 key to launch the calculator, do this:
Press the MR button. M light begins to slowly flash Press the G2 macro key. The M light will flash rapidly to indicate macro recording has started Hold down the windows key and then press R Type "calc" into the run dialog and press ENTER Hit the MR button again to stop the macro recording.
That's really all there is to it! Have fun.
