Some useful (and semi-useful) echo variables:
VARIABLEWhat Gets EchoedDescription
DATE_GMTSunday March 14 2010Current date and time at Greenwich (Greenwich Mean Time).
DATE_LOCALSunday March 14 2010Current date and time on the server.
DOCUMENT_NAME\\boswinfs01\home\users\web\b915\ez.mcfedriescom\CreatingAWebPage\ssi2.shtmlThis page's server directory and name.
DOCUMENT_URI/CreatingAWebPage/ssi2.shtmlURL of this page (less the host).
LAST_MODIFIEDTuesday October 07 2008Date and time this page was last modified.
HTTP_REFERERVariable 'HTTP_REFERER' cannot be found
Address the user came from.
REMOTE_ADDR38.107.191.91IP address of the user.
Formatting the date and time:
TIMEFMTWhat the Date and Time Look Like
%#cTuesday, October 07, 2008 10:10:03
%c10/07/08 10:10:03
%x10/07/08
%#xTuesday, October 07, 2008
%X10:10:03
%a, %b %d, %YTue, Oct 07, 2008