Redefining commands in a new environment

Question

Two questions:

1. Does LaTeX allow one to (re)define commands within a \\newenvironment? I\'ve tried using \\renewcommand, \\newcom

Answer 1

Too late perhaps, but it may be useful for someone else

\newenvironment{coolitemize}{%
\let\olditem\item% 
\renewcommand\item[2][]{\olditem \textbf{##1}\\[0.3\baselineskip]##2}%
\begin{itemize}}{\end{itemize}%
}

and use it

\begin{coolitemize}
\item[Title of my first item] Text of my 1st item.
\item[Second one] And some text here.
\end{coolitemize}

Answer 2

Sure; it's hard to know what went wrong without seeing your code. As an answer to your two questions, see if this helps:

\documentclass{article}
\begin{document}
\newenvironment{myitemize}{%
  \begin{list}{}{}% whatever you want the list to be
  \let\olditem\item
  \renewcommand\item{\olditem ITEM: }
}{%
  \end{list}
}  
\begin{myitemize}
\item one \item two
\end{myitemize}
\end{document}