In fact using UnitTest++ works already, there is one small feature missing, but it is not such a pain.
I'm sure other frameworks will work, too.
I've never used JUnit, so I don't know what are the requirements and benjamin_t never stated them explicitly.
But I guess he wants to have automatic test generation, setup, etc...
beqroson: I'm not sure what is your goal, but it is better to concentrate on something you don't like in C::B and try to fix it.
Or if you want to fix just something in C::B go to our bug tracker at berlios and choose a random bug and fix it, then post a patch.