I have had a few people ask me how I got that “currently online” thing on the bottom left of my page. As you can tell by all of my links, this site is entirely powered by MySQL database to store all of my info, posts, links, boxes, session and cookie info, everything. For the Currently online box I made a table that is populated with IP addresses and the time the address was added. When anyone loads a page from my site I gather their IP address from the Header information and place it in the table. Then a little script looks to see how old the IP address is. If it is older than 10 minutes it deletes it. Then a simple record count of the table gives you the number of unique visitors in the past 10 minutes. It’s nothing special.