I\'m using Eclipse Helios on Ubuntu 10.04, and I\'m trying to install CDT plugin on it. I download it from here here.
And then I go to Install New Software<
make sure you have GDB installed on your system...
If your using Linux based OS simply in a terminal type:
sudo apt-get install gdt
when finished downloading extract the file and install.
close your IDE (in this case eclipse and open it again and run your project.