You can have a serial to ethernet converter and try it in there or for that matter you can use a controller that has a inbuilt TCP/IP. You get a quite a lot of options for controller which have TCP/IP.
Which microcontroller are you using? Try the following development boards: matrix multimedia. they have a nice ethernet board that you can use for your applications. go to www.matrixmultimedia.com to have a look at what i am talking about