p-style column.
The varwidth package, discussed in
“automatic sizing of minipages”, provides
a solution. If you load it together with the LaTeX “required”
array package, i.e.:
\usepackage{array}
\usepackage{varwidth}
varwidth defines a new column-type “V”, which you
can use as follows:
\begin{tabular}{l V{3.5cm} r}
foo & blah & bar \\
foo & blah blah & bar \\
\end{tabular}
when the second column ends up less than 3.5cm wide;
or you can use it as follows:
\begin{tabular}{l V{3.5cm} r}
foo & blah & bar \\
foo & blah blah & bar \\
foo & blah blah blah blah blah blah
& bar \\
\end{tabular}
where the second column will end up noticeably wider, and will wrap to
a second line in the third row.
This question on the Web: http://www.tex.ac.uk/cgi-bin/texfaq2html?label=varwidcol