I can't believe I've never heard of this before. While waiting for a delayed flight yesterday someone told me about a Continental Airlines website that not only shows you the latest status of each flight, but also the status of individual upgrade and standby requests. I was able to look at the same information the gate staff was seeing at http://pda.continental.com/PDA20/default.aspx.

Do all airlines have this information available on the web?

Alaska is using the services of Flight Status. It looks like it has some of the features but I don't know it does standby/upgrades for airlines.