is there any way to tell g++ to compile all files, using a certain namespace? so that i dont have to type

	using namespace std;

in all my source files?

You shouldn't want to since it will cause portability problems with any compiler lacking such a feature, it's also a great way to confuse readers of your code.
However it can be done by placing the using directive in a header and letting the preprocessor include it automatically in all source files.

// namespace.husing namespace std;

cc -include namespace.h ...

aha, nice solution. Thanks.