I would recommend integrating Microsoft Windows XP Media Center Edition 2005 (WMC) into your home entertainment center. It's perfect for what you're trying to accomplish. WMC comes with a remote control that will allow you to control all of your computer tasks, i.e, checking e-mail, surfing the net, creating documents, etc. Your iPronto will be able to learn the remote controls from the WMC.

You'll be able to play computer audio files through your speaker system without having to leave your plasma on. In other words, you'll be able "To avoid using the plasma when listening to webradio and mp3s." And you can program this setup on your iPronto with a single soft button. You can also access Media Center while sitting at your desk using a mouse and keyboard. Nice.

This is one way of doing it, I'm sure there are other ways.