Adafruit lib for NeoPixel works fine
(tested with 10 pixel of the stripe Adafruit NeoPixel Digital RGB LED Strip - White 60 LED [WHITE] : ID 1138 : $99.80 : Adafruit Industries, Unique & fun DIY electronics and kits)
http://forum.arduino.cc/index.php?PHPSESSID=ei2ghoroto35godf46e01t1en4&topic=144446.60
Even without level shifting the 3.3 V due pin to the 5 V input pin of the Neo pixel,
but not sure how stable this will be (datasheet says 0.7*Vcc min. for Vih = 3.5)