ASP.NET File Upload with *Real-Time* Progress Bar

I had a number of people email me asking how the ProgressBar Toolkit control I blogged about last month could be used to provide progress for file uploads. So I thought I would spend some time and see how this could be done. Thankfully, there are a ton of resources available on the internet that discuss this in pretty good detail. But I didn't see any good examples of how to include the real-time count of the number of bytes that have been transferred. So I thought I would try to tackle that problem while building my example.