I recently purchased a Nokia N800 Internet Tablet. Nokia, which is generally known for cell phones, has a nice device in the N800. It isn't a phone itself but pairs up easily with a Bluetooth enabled cell phone for Internet access, or you can use WiFi. It has an excellent connection-manager: finding WiFi hotspots and changing connectivity profiles is extremely easy.
The device has a version of Opera running on it. Because of that and a fairly high-resolution screen (800 pixels across) you can browse most standard web pages without much scrolling. It has built-in Flash support, so you can even view YouTube on it.
It is running a customized build of Linux, and there is a large open-source community building software for it. You can also use a variety of Bluetooth accessories; I'm typing this post on a Stowaway Bluetooth keyboard paired with the N800.
It isn't completely consumer friendly - there are some rough edges, but if you are a geek looking for a great way to get online quickly and from nearly anywhere without the limitations of a web browser on a mobile phone, this is a great way to go.