If you run HomeSeer on your home PC then it can generate a web based front end to your home automation setup - the iPronto can then be pointed at that web based front end via one of its browsers if you wish. (I don't use HomeSeer but I have used the iPronto at a friends place and he does use it and it worked fine.)

Alternatively you can define normal buttons on the remote control screens as you would for any other device command and have the iPronto send out the X10 IR commands to be picked up by an IR->X10 converter such as an IR7243.

I use a combination of both an IR7243 for direct control of some items (local lighting) and the web interface of HomeVision.

Phil