Plug the PC in to the blue part of the strip. Plug the devices you want to power up in to the white parts. Set your BIOS to start on keystroke. Make sure you have a PS2 connection to your IPAC or whatever device you are using to connect your joysticks. Plug the strip in to the wall, move a joystick and the computer will come on as will the devices you plug in to the white part of the strip. Turn off the computer and the PC will turn off as will the devices plugged in to the white part of the strip.
If you were just looking to hook up a switch, you wasted money on the smart power strip. You could have taken any ole' $5 strip, pulled it apart, disconnected the switch that comes with the strip, add some wire and the switch you linked to above, and you would be golden. That is EXACTLY what I did with my two stand up MAME cabinets. My cocktail uses the smartpower strip but because I am a dumbass and got the USB Ipac, I can't power it up with a flick of the joystick...I use a standard HAPP button to power it up. I have an external stereo also hooked to the smartstrip as my cocktail doubles for a jukebox and when I power up/down it also powers up/down the external stereo amp.
Here are some pix of my $5 power strip solution.
Please keep in mind that you are dealing with 110v and you do not want any metal from the wires exposed. The two black wires you see going up the side of the strip lead to the switch you see at the next picture. I flick on the switch its as if I switched on the power switch on the strip. Works nicely.
PS: The toggle switch you see at the top of the cabinet is the stock switch that is still hooked up directly to the monitor and marquee. So if I want to leave the PC on but turn off the monitor and marquee, I can flip that switch. The switch at the back of the cabinet is the one I added.