There are a few options
1. the cheapest option would be to buy a basic ir remote of trademe which comes with a usb plug (these do not allow power on/off via remote and also take up a usb port)
2. PS3 toothfairy which would cost around NZ$120 each to import 3 including shipping. (quite pricey) allows full control of PS3 all commands including on/off and doesnt use a USB port
Also has port for ir in the back for people with structured cabling etc so it can be controlled from anywhere in the house.
3. IR2BT pretty similar to toothfairy possibly a bit cheaper when it comes in stock.
Anybody else know much about this/ interested in getting one / already got one