3g S vs 3g speed test help...

Depends on the type of speed you're comparing. If you're only interested in CPU speed, measure launch times and/or app performance. Measure how long it takes yours to start up compared to his (after turned off). See how long it takes to launch a complex game (such as Peggle). Compare frame rates in 3-D games. How fast a webpage loads may or may not be a good measure of the CPU since caching can come into play (i.e. if he visited the site and you were going for the first time).

Bottom line: The 3GS is far faster than the 3G in nearly all CPU-intensive situations.

If reception is better with one carrier than the other, the internet connection speed will generally be better also. At a given time when connected to the internet via the carrier's 3G network depending on how many other 3G phones are connected to the same tower or towers actively accessing the internet at the same time, and the same if any laptops with laptop connect cards are doing the same, or those who may be tethering their laptop with their cell phone, the internet connection speed will vary.

I use cable modem service at home, and depending on how many others with the same service are actively accessing the internet in the same general area at the same time, my download and upload speeds will vary.

It would be a better test if both iPhones are using the same carrier, so try this when both iPhones are connected to the same wi-fi network.

There is a free Speed Test app at the iTunes store. Seems to test upload and download speeds. Perhaps not what you're after though.

Phil