AC charger for USB devices - what about the data pins

[George]

I've ordered a Sandisk Sansa Clip MP3 player, which charges through
the USB connection to the computer. I need a wall wort AC charger
for this device, and possibly for other devices in the future, and
actually have everything I need for that, including a linear 5V, 1
amp, regulated brick supply and a USB type-A socket.

But I don't know what I should do with the data pins - pins 2 and 3.
Should they just be N/C? Should they be tied together, tied high,
tied low? Does it matter?

According to this link:

http://www.usbmadesimple.co.uk/ums_3.htm

an actual upstream USB port (i.e.- the computer) would have these
data lines tied low through 15k resistors.

Does anybody know how these lines are actually handled by a typical
AC USB charger?

Thanks for any suggestions.