I have been using an HTC Magic phone for two months. It is powered by the open source Android mobile operating system that Google was involved in creating.
My experience is that the platform provides excellent access to Internet services such as browsing, searching, accessing email and contacts (via Gmail or other web account), and it also performs well as a phone.
I think the killer features are:
- Unified contacts list via Gmail - no more scattered contacts between phones, PDAs, laptops and email clients
- Tethering is available without hacking the phone so you can use it as a modem
- Integration with Google maps and GPS. You can hyperlink to maps directly from contact and calendar addresses, and use Google Maps to navigate there.
This Greenlivingpedia article provides more details.
In summary, I thin that Android has many features that make it superior to an iPhone, and many of the handsets are cheaper. You also now have a wider choice of handsets, including Samsung, HTC, Motorola (the Droid) and now even Google with its Nexus One (currently only available in the United States, and is manufactured by HTC).