Hi everybody,
I think it would be so much simple to use this kind of stuff "Remote Control using the Audio Port":

http://www.codeproject.com/KB/mobile/PocketBeamer.aspx

The device looks pretty simple and it should not be expensive, and does not require anything else. As simple as outputing audio, except that it should be 40 KHz

edit:
The device is as "Total Remote" from Griffin Technology but it's discontinued...and was only 26$.