The gcc suite that comes with OS X can apparently compile C++, amongst other things. The IDE isn't too bad either, and includes a GUI editor (of sorts).
Actually, XCode 1.5 is very, very nice. It supports Objective-C, C, C++ and Java (both Cocoa-Java and standard Java), and has support for many other languages such as Ruby, Pascal, AppleScript, and Fortran.The GUI Editor (Interface Builder) is extremely powerful, especially when used in conjunction with Objective-C.