I have one of these Energizer Energi To Go I used with my Nokia E71 (had the 2.5mm power cable). Connected it to the Nokia CA-146 and lo and behold, it charges my N900! Good solution, IMO. I also have a Kensington power pack ( http://us.kensington.com/html/13883.html ) which, unfortunately, won't charge they N900. Worked fine with my E71 and my Zune, however.