Forum Moderators: open
<edited typo>
1 Going to an external site.
2 Enlargements of photos
3 Small bites of supplementary information (definitions for example) that don't strictly fit within the flow of the parent page, but that I would read and then return to the parent page - I don't expect to see further links on that new window.
Daisy chains really tick me off. :)
It's a lot harder to suppress a new window which automatically pops up. Believe me, there have been times when I've had 10-15 MSIE browser windows open, and it's bloody annoying when the site I'm browsing decides that it wants to open a new window for every external link I investigate!
A nice little tidbit: tack a little "URL arrow" image to the end of an external link, that way users can more readily notice which is an external link and which isn't. But really, users should be able to see that for themselves in any case just by looking at the status bar on mouseover.
And of course there are accessibility issues too. Users with impaired vision who may have special browsers can get completely thrown by new windows.
If you add in the fact that more advanced users (like us) have figured out how to open a page in a new window then there isn't really any need to do it in general web sites.
Originally I had thought it would be easier for users as they can see a list of articles click, read them in that new window close it and they are still at the article menu.