Well, I just tested it. What you have to do for the LePan II is tie the two data lines together - no resistors.
So it's very easy! I took a USB extension cable I had ($1 at Dollar Tree!), cut it to a shorter size, and tied positive to positive, ground to ground, left the two data wires disconnected on the power supply side, and tied the two data wires together on the LePan side. Voila!
Now you have an adapter, so you connect the LePan USB cable to one end, and the power supply to the other. In my case, this is a car adapter I bought at Walmart for $12 (i-xt) that supplies 2A on one connector. It also has a 1A connector for another toy.
Note that to make it even easier, you should carefully cut the insulation on the extension cable and leave the positive and ground cables intact. Just cut the two data cables and join the two on the LePan side and you're done. Of course, you have to figure out which is which.
Have fun!
Alex