My opinion? Large no no. I've noticed shopperuk.com (large affiliate I'm sure) do it but from a users perspective, everyone hates pop ups. Plus most will just get blocked anyway, as the one from shopper uk has been. I think from a users perspective this is even worse - they will be wondering why you tried to open windows, what they were and why they were blocked.
Its pretty pointless now, as most browsers, toolbars, anti virus programs and firewalls have popup blockers built in. I have 3 different bits of software blocking pop ups on my system, and thats without a concious effort to install any.
Before popup blockers were routinely built in to software though, I used to shut down any sites instantly that opened a popup as a matter of principle, and I expect a lot of people are the same.
There are far more effective ways of advertising, popups have been and are long gone, don't waste your time on them
Personally I hate popup ads. I'm surprised at the number of big name websites that still use them. Autotrader and Multimap spring to mind, but I've seen many more.
Gives you extra space on your page, and it's new and different. Only started using them myself for a day or two so can't comment on how they affect sales, but from what i`ve read they can be very effective.
Very easy to install, you just need to do a small image and large image for the page curl and reveal, and change the javascript to point to these files. Add the normal script tag to your page in the header, and it does everything for you! Note that the images are just standard images, the reflection and curl etc is all done for you by the swf (flash) files.