or, more simply (but not rolled into the identity transform),
<xsl:template match="a">
<a href="http://{(_at_)href}">
<xsl:apply-templates select="*"/>
</a>
</xsl:template>
... simpler, but if the <a> elements had any other attributes (e.g. title,
target) they would be lost.
XSL-List info and archive: http://www.mulberrytech.com/xsl/xsl-list