One of the first things your website needs is a counter to track your visitors. Knowing how your visitors are finding your site tells you which of your promotional efforts are working, and which are not. When the server where a counter lives goes down, it can't register the hit. When the Internet is congested, it might simply take too long for the counter to load.
Most counters are images.
TheCounter Great Statistics, good layout. Tells you where last 10 visitors came from. ColdFusion Visitor Logging System Basic Statistics, requires installation on server. No image required, though. This site was cobbled together by the crazy folks at Wondermill .