Internet traffic data can be collected in a variety of ways. One way is to monitor the flow of data packets through network access points (NAP) and routers, another way is to systematically ping specific servers and measure the response. Here are a collection of sites that give multiple views of Internet traffic.

MIDS Internet Weather Report
Offers a variety of animated maps showing Internet traffic statistics, in image formats (GIF, MPEG) as well as in Java.

Internet Weather Report
This site runs automated ping tests of servers at the top network service providers every 15 minutes. The resulting display if packet loss gives an idea of Internet traffic along various connections.

Internet Performance Measurement and Analysis
Real-time graphs and trends of Internet traffic statistics based on data collected at network access point (NAP) routers.

100 Hot Websites
A collection of lists of the top 100 Web sites in a variety of categories. Included here because the lists are based on "objective estimates of web traffic."

Chicago NAP (Ameritech)
Daily usage statistics from Ameritech's network access point in Chicago.

National Laboratory for Applied Network Research
Daily usage statistics from the network access point in New York.

Internet Information Presentation
Links to a wide variety of sites devoted to the acquisition and visualization of network data.

Tutorial: Insight Into Current Internet Traffic Workloads
Interesting information and observations about data gathered by these services.

You can always check traffic in real-time between your own computer and an Internet server with a traceroute program.