Not sure why minipage did not work for you:

Note:
Code:
\documentclass{article}
\usepackage{amsmath,tikz}
\usepackage{etoolbox}
% https://tex.stackexchange.com/questions/36954/spurious-space-above-align-environment-at-top-of-page-minipage
\makeatletter
\pretocmd\start@align{%
\if@minipage\kern-\topskip\kern-\abovedisplayskip\fi
}{}{}
\makeatother
\begin{document}
\begin{minipage}{0.30\linewidth}
\begin{center}
\begin{tikzpicture}[xscale=.5, yscale=.5]
\draw [->,thick] (0,0) --(3,4) node [right] {$\bar{u}$};
\draw [->,thick] (0,0) --(5,0) node [below] {$\bar{v}$};
\draw [->,thick] (0,0) --(0,4) node [left] {$\bar{w}$};
\draw [->,thick] (0,0) --(3,0) node [below] {$Pr_{\bar{v}}\bar{u}$};
\draw [dashed] (3,0) --(3,4);
\draw [thin] (2.5,0) --(2.5,.5) --(3,.5);
\end{tikzpicture}
\end{center}
\end{minipage}%
\hfill%
\begin{minipage}{0.65\linewidth}
\begin{align}
Pr_{\bar{v}}\bar{u} &= \frac{\langle\bar{u},\bar{v}\rangle}{\langle\bar{v},\bar{v}\rangle}\bar{v} = \lambda\bar{v} \
\bar{w}+Pr_{\bar{v}}\bar{u} &= \bar{u}\
\bar{w} &= \bar{u}-Pr_{\bar{v}}\bar{u} \
\bar{w} &= \bar{u}-\lambda\bar{v}
\end{align}
\end{minipage}%
\end{document}
Another option is to place the picture within a varwidth environment which has the advantage that you only need to tweak the size of the minipage containing the align which allows you to control how far the math content is.

Notes:
- Even though the
varwidth environment has a length specification, the box will adjust to the natural width of its contents.
- You could or course use the
varwidth for the math content as well, but then you don't have as much flexibility to move the math content closer to the picture (unless you use an environment different spacing than the default align.
Code:
\documentclass{article}
\usepackage{amsmath,tikz, varwidth}
\usepackage{etoolbox}
% https://tex.stackexchange.com/questions/36954/spurious-space-above-align-environment-at-top-of-page-minipage
\makeatletter
\pretocmd\start@align{%
\if@minipage\kern-\topskip\kern-\abovedisplayskip\fi
}{}{}
\makeatother
\begin{document}
\begin{varwidth}{\linewidth}
\begin{center}
\begin{tikzpicture}[xscale=.5, yscale=.5]
\draw [->,thick] (0,0) --(3,4) node [right] {$\bar{u}$};
\draw [->,thick] (0,0) --(5,0) node [below] {$\bar{v}$};
\draw [->,thick] (0,0) --(0,4) node [left] {$\bar{w}$};
\draw [->,thick] (0,0) --(3,0) node [below] {$Pr_{\bar{v}}\bar{u}$};
\draw [dashed] (3,0) --(3,4);
\draw [thin] (2.5,0) --(2.5,.5) --(3,.5);
\end{tikzpicture}
\end{center}
\end{varwidth}%
\begin{minipage}{0.5\linewidth}
\begin{align}
Pr_{\bar{v}}\bar{u} &= \frac{\langle\bar{u},\bar{v}\rangle}{\langle\bar{v},\bar{v}\rangle}\bar{v} = \lambda\bar{v} \
\bar{w}+Pr_{\bar{v}}\bar{u} &= \bar{u}\
\bar{w} &= \bar{u}-Pr_{\bar{v}}\bar{u} \
\bar{w} &= \bar{u}-\lambda\bar{v}
\end{align}
\end{minipage}%
\end{document}
\documentclassand the appropriate packages so that those trying to help don't have to recreate it. – Peter Grill Feb 27 '13 at 19:37