Here is a picture of the system structure

I chose an ATmega644 because it has two serial ports. I needed that because the RN131 uses one and the FT232 uses the other one. 

The RN131 was at that time the best available solution for WiFi. Although, it did for example not support all types of wireless networks. If I remember correctly WEP64 was not possible. Not that you'd want WEP64 as encryption for your wireless network, but that's a different thing. Another thing I noticed in a different application is that the RN131 dropped characters if the WiFi signal strength was low.

The display is a nice DisplayTech 204A; 4 lines of 20 characters, the chosen version has a black background and white text, really nice. The picture of the project doesn't do right to the beauty of the display.

An FT232 is more or less your standard choice for USB to serial. It just works, it's simple to incorporate in a design, it is supported on all operating systems and, maybe because of all these reasons, really widely used.