If you believe bigger and more features is better - you will love this robot project. The mjolnir robot is a very large tank chassis that has many functions. It is controlled using text commands via TCP/IP - and the robot carries a wifi router connected to an Ethernet-enabled Arduino board for communication. There is also an IP-webcam to relay images back to the user, which can also be controlled remotely. Mars rover eat your heart out. Furthermore, the creators have made a detailed short documentary about the robot as shown below:
You can find everything you need to know about the mjolnir robot on the project page. And we're on twitter and Google+, so follow us for news and product updates as well.
Looking for an Ethernet-enabled Arduino board? Look no further - we have the outstanding Freetronics EtherTen. Apart from being fully Arduino Uno-compatible, it has onboard Ethernet, microSD socket, full USB interface (so you don't need a costly FTDI cable just to upload a sketch!) and supports optional Power-over-Ethernet: