What kind of things do you prefer? Databases, science, math, web? At first, make sure you have Bjarne Stroustrup book (very important: last edition). If there's anything good in C++, it's there. Look also at his homepage: http://www.research.att.com/~bs/homepage.html Bjarne is the guy who first started C++, and in a certain way still leads its development.
What kind of things, barring coding on Haskell-less platforms and library interfaces would you choose to do in C++?
I'm asking 'cos I'm learning C++ and can't get the proper motivation to do any program I can think of in it: If I need abstraction, I'm thinking Haskell or Scheme, and if I'm thinking performance, C itself more than suffices.
Plus template programming makes me shudder because of its atrocities against clear and straightforward FP, but that's a different matter.
Coming to think of it, a compiler from a clean syntax to C++ templates sounds like a fun project... which I'd do in Haskell.