Airbnb (YC W09) launched an iPhone app
airbnb.com
airbnb.com
It doesn't look much but the customization of all these standard UI elements (e.g. UITabBar as mentioned by sudont) makes a difference in the end. I would say especially in their market where I have seen websites with more than dubious interfaces.
It looks like the "Daily Deals" are exclusive to the app?
I've had around 20 people stay at my place through airbnb and I think one person had an iPhone. At least in NY, many people visit from overseas where iPhones are not as prominent.
OTOH, Managing bookings on my iPhone is gonna be sweet.
Other platforms are also very interesting to us, and we saw this as a good first step into the mobile space.
I'm also a host (www.airbnb.com/rooms/12157) and know what it's like to manage a listing on the go. The app includes a first round of features that we feel will make hosting easier, including messaging, guest scheduling, and instant push notifications.
I tried to use Airbnb recently and although I understand there's a business reason for not being able to contact other people in this website directly, e.g. via email or phone, I found the means by which the website tries to prevent it very annoying. It's not that I wanted to cheat them out of their provision, it was merely for convenience.
Pity, because the service is good and exceptionally well designed. But it is not the open Internet I am wishing for. Waiting for a better competitor.