Does your Internet connection ever feel sluggish? Do you want to know if the problem is just with a particular set of server or with your connection in general? Well, now you can find out with with this handy app that MacDerm sent me: Speedtest.net.
Speedtest is a Flash application that lets you test your download and upload speeds to a host of different severs in various geographic locations. After you run your tests, you will get stats for both your download and upload speeds and comparisons on how your connection ranks against others.
I think a good idea would be to run this when you are getting peak performance as a baseline. You could run it again later if your connection is feeling sluggish to see how you are differing from the baseline. Of course, all of this is academic, as you can't really do anything about your connection being slow at a given time. :)
I'm very curious as to how this works. It seems that you download a somewhat large file and then upload it back to the server you're testing against. Can Flash do that - upload files without user intervention?
Anyway, definitely worth checking out.