To other Arduino/Winbond interfacers and anyone else who is interested in trying out this project, here are some hints/tips/tricks worth trying:
1. The ISD1760 COB seems to have problems interfacing with the Arduino, no matter what. I've been back and forth with the Winbond guy about this and, despite checking timing, software (my code,) hardware configurations, scope traces, etc., I still can't get the COB to work.
2. However, I have gotten the ISD1760 PDIP to work with the Arduino using unsped's code. For anyone who might claim that his code doesn't work, I will defend it, as I've checked it up one side and down the other!

For example, his SPCR is correct, although you can TRY changing the SP0 and SP1 if you want to mess around with the timing. (I've got mine set at 11, which, if you check out the Atmega168's data sheet, means the Atmega's fosc is like 8/128 Mhz or something - long story short, it's a nice slow, steady clock rate.)
If you've connected everything in the push-button configuration found in the ISD1760's data sheet, you've verified your SPI connections between the ISD1760 and the Arduino and you're STILL not getting anything, try putting a 10kohm resistor (or higher, I've been messing with the resistance and had varying timing results) between pin 7 of the Winbond (the SS) and the GND of the ARDUINO. I'm not sure if this causes any sort of charge buildup, but I do know that all of my capacitors have remained relatively cool for about a half-hour of operation, so I don't think I'm burning anything. Somebody can correct me on this if you want.
The important point about the above is that, at least for me, it got the Arduino/Winbond SPI interface working. I've got plenty of notes about getting these puppies to talk with each other, too, so I'll try and post them over the next few weeks as well.