./configure --with-java --with-mysql --with-gd --with-apache=../apache_1.3.11 --enable-track-vars --enable-sysvshm --enable-bcmath --disable-debug --with-xml

Using Blackdown JDK 1.2.2

From php.ini:
[java]
java.class.path=/usr/local/lib/php_java.jar
extension_dir=/usr/local/lib/php/extensions/no-debug-non-zts-20000809
extension=libphp_java.so
java.library.path=/usr/local/jdk1.2.2/jre/lib/i386:/usr/local/jdk1.2.2/jre/lib/i386/native_threads:/usr/local/jdk1.2.2/jre/lib/i386/classic:/usr/local/lib/php/extensions/no-debug-non-zts-20000809

Test script:
<?php
$system = new Java("java.lang.System");
print "Java version=".$system->getProperty("java.version")." \n";
print "Java vendor=".$system->getProperty("java.vendor")." <p>\n\n";
print "OS=".$system->getProperty("os.name")." ".
$system->getProperty("os.version")." on ".
$system->getProperty("os.arch")." \n";

$formatter = new Java("java.text.SimpleDateFormat",
                      "EEEE, MMMM dd, yyyy 'at' h:mm:ss a zzzz");

print $formatter->format(new Java("java.util.Date"))."\n";
?>

The first 3 runs of the above work as expected. The fourth run gives the 
error: Fatal error: Unable to create Java Virtual Machine in /home/torben/public_html/php3test/tj.html on line 2.

Setting MaxRequestsPerChild to < 3 in httpd.conf makes the problem go away, but this is obviously a suboptimal solution. :)