Tree like items list

Quick hack with Tikz, I'm sure this can be improved/made more general with some work:

\documentclass{article}
\usepackage{tikz}
\usetikzlibrary{shadows}

\newcommand{\mylist}{\tikz[overlay]\draw(-.2,-.2)--(-.2,.5) [path fading=east](-.2,.15)--(.1,.15);}
\newcommand{\myitem}{\item[\mylist]}
\begin{document}
\begin{enumerate}
   \item Google
   \begin{itemize}
      \myitem Picasa
      \myitem Feedburner
      \myitem Youtube
   \end{itemize}
   \item Microsoft
   \begin{itemize}
      \myitem Corel Corporation
      \myitem Zignlas
      \myitem MyBlogLog
   \end{itemize}
\end{enumerate}
\end{document}

My answer builds off of dcmst's answer. I've reused his tikz code.

If you want to redefine all second-level enumerate environments to use this symbol, you can add \renewcommand{\labelenumii}{\mylist} to the preamble of your document.

\documentclass{tufte-handout}

% From dcmst's answer at <http://tex.stackexchange.com/a/175204/80>.
\usepackage{tikz}
\usetikzlibrary{shadows}
\newcommand{\mylist}{\tikz[overlay]\draw(-.2,-.2)--(-.2,.5) [path fading=east](-.2,.15)--(.1,.15);}

% All second-level enumerated lists should use the \mylist bullet.
\renewcommand{\labelenumii}{\mylist}

% This generates fake lists for us.
\usepackage{blindtext}

\begin{document}

It works okay if you only use a second-level list.

\blindlistlist[2]{enumerate}[3]

If you use a third-level list, you'll have to do something a bit fancier.

\blindlistlist[3]{enumerate}[3]

\end{document}