Adding a remote to a G4 Imac?

Hi folks,

I have a 4-year old iMac G4 1.25Ghz on which I am running Leopard.

It is used as a second machine these days and is mostly used for Itunes/watching DVDs/listening to internet radio. I'm also planning to get a slingbox to stream TV to it.

I would really like to be able to remotely control it so I can use front row in exactly the same way as I can on my more up to date machines, but of course due to its age it never had the apple remote function.

Anyone know of a similar product that I might be able to use, perhaps through a USB dongle? I done a search but haven't turned up anything.

Thanks in advance.