valgrind.el adds a valgrind command to Emacs, which will run the given valgrind command, and parse the output as in compile mode, so you can click on lines (or hit C-X Enter) to jump to the source, or use "C-X `" to go through them one at a time.
At least for me, Valgrind doesn't print out full paths, and so every time you try to jump to an error it prompts you for the file location. That makes things much less convenient. I have fixed it for myself by using a small patch to make valgrind print out full pahts; YMMV.
It is based on the compilation mode included with emacs (compile.el), and as such it is licensed under the same GPL license as Emacs. It is inspired by some ideas from the blog post Cool Emacs Trick on The Cliffs of Inanity blog.