Make continuous switch momentary?

Is there an easy way to do this? I can find a lot of examples for latch circuit (basically the opposite of what I want).

Sure, just look for changes, either low to high, or high to low. i.e. is the state of the switch different to last time you looked? (or did you mean mechanically?)

this is also something I have been curious about. :)

I am curious not mechanically ,but from a code standpoint..

In my mind.. code wise.. does it matter the switch type?

Maybe Im over/under thinking it as I have never tried..

AWOL: Sure, just look for changes, either low to high, or high to low. i.e. is the state of the switch different to last time you looked/ (or did you mean mechanically?)

This would be easy with an arduino, but my friend's project does not use one. I am helping her build one of these:

http://volpinprops.blogspot.com/2010/11/portal-gun-for-childs-play_22.html

Using this sound board:

http://www.replicaprops.com/Sound-board-for-props-and-costumes-model-4M_p_64.html

My problem is that the on/off switch is DPDT (turns LEDs on and off), but should also trigger momentary pulse to the pins on sound chip for on and off sounds. It works with continuos current to pin (doesn't repeat sound or anything), but a momentary switch is spec'd.

This would be easy with an arduino,

Well, yes, this is an Arduino forum.

What about using a 555?

I realize that, but I thought it would be OK to ask in General Electronics section.

for OP: (maybe this)

http://www.pololu.com/catalog/product/750

anyways... Im still interested in have a conversation/enlightenment on the Arduino way to handle switches in code?

Anyone have a quick code/sketch sample to look at for using/detecting a latching/vs momentary switch?

thanks