Then you will run into problem of too low amount of power, to drive more omni-directional diode - it may work, but for a change, you will end up with beam of ~70 degrees coverage, but requiring to be 20 centimeters from receiver

I have tried that myself, once (also putting diffusing lens from old remote, in front of N900's one), and it just won't work. Only one feasible way is to build small IR blaster/repeater, which gets commands from N900's IR transmitter, and repeats them using powerful beam. (this way, you build powerful IR cheaply, that can still make use of awesome programs like Pierogi).

/Estel