That would be the DC-10, a rather chunky thing. BTW, why does Nokia no longer have any technical info on products like this on their website?

Of course Nokia says nothing about the currents, though they do claim this combination works.

By the way, I tried to get a word to a friend-of-a-friend at the Nokia development department, asking that logging about this kind of events (for example, the dialogue between devices over the MicroUSB port) be made available to the user, so that cases where it doesn't work won't stay "this just doesn't work" type mysteries. For example, it turns out quite a lot of the "no name" brand USB charger devices return more or less random device types to the N900, which often will refuse to talk to them because of this.