Places where i like or would love infinite scroll:
->Google images results
->Google search results.
->Facebook/Twitter feeds when i am going through feeds.
->Question answer sites, blogs, articles, etc.
Places where I hate or would hate infinite scrolls:
->Facebook feeds when i have paused a video in between and now i face immense problem to find it again.
->If gmail inbox has infinite scroll things would get really messy for me.
->If books kind of interface have infinite scroll, nah 1000 pages with infinite scroll no.
But what I would rather love would an advanced scroll bar. Different uses will have diff requirement.
With advanced I mean is that in case of Facebook feeds I have some color coding or may be whenever a video is paused it indicates on the scroll bar. And I can directly go there and watch all the videos. Better it can color code the scroll bar with places where I have links and wall and tags with my name and photos. Something similar to how chrome does when we Ctrl+F find something on a page.
Similarly in case of books I would like each page to be differently marked on the scroll bar, so that I can click and go to one particular page (may be with numbers also) and as I scroll down the number becomes smaller. When I hover on a location of scroll bar it shows me magnified page number.
If Gmail inbox implements infinite scroll then the scroll bar must have markers with date and time of received mail so that I can go to a particular location easily.
Something about Facebook timeline, they have beautifully implemented infinite scroll with a year base scrolling option on the right.