R help - May 2006 - outline polygons of point clumps

Dear all,

How to generate one outline polygon for each point clump? Are there
any present functions in ArcView, ArcGIS, R or some freewares? I just
had a quick look at the package adehabitat and did not find the
function.

To my knowledge, I could do it as follows: 1) make a grid map of my
study area with cell values = 0; 2) assign 1 to the cells containing
at least one point; 3) convert the 1-value cells into polygons.

Am I right?

Thanks
Xiaohua