I still don`t use cout and cin actually. I prefer printf. I don`t know what are streams exactly (but I bought Bjarne TC++PL and it will arrive next thursday, and then I will read what it is...)
In fact, I still rarely use std, when I use it is vectors.
I never used std interators (I think they are fugly, and I like to use while() instead of for )
And I don`t know what else std do beside iterators, streams and containers.
Lot's of people prefer printf to cout/cin.
Iterators in my opinion are a bad idea because there are so many cases when you need to do index arithmetic. The idea of having common interfaces for data structures with very different performance characteristics is one that probably seemed great to some people at the time but it doesn't work too well in practice.
The C++11 standard library seems to have a lot more features that may be very useful, like regular expressions, but I haven't started using it yet and if you care about cross-platform code it probably won't be truly useable for several years.
EDIT: Had a nagging feeling I was forgetting something when I wrote this. Yes of course std::map is incredibly useful it's definitely something one would need to implement if it weren't in the library.
C++11's type inference does make STL iterators a lot less ugly, by the way. Also (referring to the initial post), there's no reason you have to use for rather than while when using iterators (while(v != c.end()) ...).