Yesterday and today I did a couple of checks on my iPhone 3GS bandwidth using Speed Test. I was literally at my office seat both days and the time of day was around 11am and performed 2 test runs each day. Yesterday, my throughput was 760/121 & 749/114. Today it was 1129/215 & 1958/329. Wow, that's quite the difference. I could also "feel" the difference in browser performance between the two days - obviously not scientific but tends to back-up that there was a significant difference. I wonder if other providers have these wild swings in bandwidth?