i grabbed 2 of these the other day from Amazon and i'm really happy to report that unlike most usb hubs these ones really do work as advertised, as soon as they arrived i plugged one into my wii and set about testing wii speak, wiimotion camera, usb memory stick and rockband and disney mics, all worked flawlessly, then i switched to the xbox 360 i plugged the hub into the only spare port on my 360 (the other 2 are used by kinect and the hd-dvd drive with wifi + live vision camera plugged into the hd-dvd players extra ports) again i tested a variety of add ons including mics, big button controller receiver, usb hdd and the wireless headset adapter, again everything worked.
now, me saying that everything worked may sound pretty obvious but in fact i've tried 3 other usb hubs (powered and not) and none of them has worked on either the wii or 360, i cant say if these will work on the ps3 as well since my ps3 only does linux as sony decided to remove its other features.
you may wonder why i marked it down by a star? well the supplied usb lead is about 2cm long meaning that when 4 devices are plugged in its going to put one hell of a lot of strain on the consoles usb port so in reality you'll need a short usb extension cable.