We’ve had a bit of a debate going on here about the role of mobile websites. Ollie wrote an interesting post on this topic late last year, decrying the use of mobile sites and arguing that mobile devices should adapt to the medium rather than the other one around.
I take Ollie's point that sometimes the cut-down mobile versions of sites can be very annoying. I find http://mobile.theage.com.au quite frustrating because it is too cut-down. But I find visiting the main website of The Age on my iPhone even more frustrating - it freezes up, it's slow, and it's hard to navigate.
At the same time, there are some cases where the mobile site offers a much better iPhone experience than the main website. Facebook and Twitter are excellent examples of this. The mobile versions of each have all the features you need, but they load much faster because they have less markup and they are easier to use because all the UI elements are sized properly for the iPhone browser.
Another example is blogs. Last year one of my favourite blogs, ZeroHedge moved from BlogSpot (which automatically creates a nice mobile version of the blog) to some other platform which doesn't. It used to be easy to use on an iPhone but now it is close to impossible. Compare http://zerohedge.blogspot.com to http://www.zerohedge.com on your iPhone.
Google Reader is a final example. It has such a good site - specifically made for iPhones - that I think I actually prefer to use it on my iPhone rather than the main web-based one. And I'm not sure that the main web-based one would even work on an iPhone.
So I think mobile-friendly sites do have a role to play in today's digital marketing mix. To create a compelling mobile experience right now we do need to adapt the medium to the device. I love my iPhone as much as anyone, but at the end of the day it still has a much smaller screen and a much slower processor than the Macbook that sits on my desk. Until the iPhone can display websites as well as my Macbook can then I would encourage brands to keep making mobile-friendly sites.