Good question Armen, and I'll be interested to hear other people's answers.
In my book, infinite scrolling is only a wise choice when the user doesn't care how many items there are. The perfect example of this is Twitter, where the average user probably doesn't care how many tweets there are – they will scroll downwards for as long as they want to, and then they'll do something else. The more hardcore Twitter user probably has a different application (like TweetBot) to read tweets, so they can catch up on Twitter in a different and more methodical way.
I've worked with some companies and colleagues in the past few years who have insisted on using infinite scroll on websites, even though it makes it really hard for the user to have a sense of where they are in the product listing, and how many more products there are, and they also can't bookmark a "page" of products and come back to that page later, to continue browsing – they have to start at the top again.
When I worked with Country Road on their new site, there was a requirement to have infinite scroll on their products. I wouldn't have recommended this, but it was a requirement. As you can see from this page, I recommended that they add in a fixed navigation to infinite scroll pages that shows users where they are in the product listing (e.g. 1-48 of 88), and gives them a way to jump to the top of the page. I didn't recommend a button to jump to the bottom of the page, because in any one category, there wouldn't be a long enough page that would prevent the user from getting to the footer easily.
