As per Elsevier's
<a href="http://authors.elsevier.com/"> Copyright information:
What rights do I retain as author?, </a>
copies of my papers published in Elsevier publications are made available in
electronic form at this Web site. Elsevier's policy says:
<ul>
<li>
As an author, you retain rights for large number of author uses, including
use by your employing institute or company. 
<ul>
<li>
The right to retain a preprint version of
the article on a public electronic server such as the
World Wide Web. Elsevier does not require
that authors remove from publicly accessible
servers versions of their paper that
differ from the version as published by Elsevier. See
also our information on electronic
preprints for a more detailed discussion on these points.
<li>
Posting of the article as published on a public server can only be done with
Elsevier's specific written permission.
<li>
Requests to post published articles on public servers are considered on a
case-by-case basis.
</ul>