I'm sitting at the cafe (which doesn't have WIFI) and doing some work. For instances like this, I use a non-sanctioned tethering app - HandyLight (one of the best $0.99 apps ever). Don't bother looking for it - Apple yanked the app on July 20, 2010. It takes a few semi-complicated steps to get everything setup but once you've gone through it a few times, it takes less than 30 seconds to tether your iPhone to your laptop. One thing I did notice was that things seemed to be slower than usual when surfing on my tethered laptop. I did a quick speed test and noticed that the download speed on my tethered laptop was almost 33% slower than directly to the iPhone itself. Upload speed was almost 40% slower. Not sure if the physics behind tethering means there will always be this speed degradation no matter what method you use - sanctioned or unsanctioned. If so, the value proposition of paying $20 EXTRA a month to tether your laptop to your iPhone seems much less appealing.