X10 dimmer + IR-to-X10 converter.

Use the IR543 or IR543AH to send X10 powerline commands triggered by IR from your iPAQ H3850.

PDA-rf is unlikely to ever come to market. I think the costs of regulatory approvals will exceed the potential return by several orders of magnitude.

Or you could build this...

   [Link: laser.com]

and have it convert the IR to 433.92MHz RF and broadcast it to X10 RF modules like the TM13.