Probably not relevant, but I thought I would mention it. Recently, I was trying to use the "free" wifi at a hotel, and the throughput was at best on par with 2400 baud, let alone 56k.
What had happened was an IT guy from my client had configured the DNS to work with their internal wifi network. I didn't realize that these settings overruled anything else. When i restored the settings to default, it worked like a charm. It was a pain to have to reconfigure to their network at the start of each workday, but not the end of the world.