Identifying a palm tree

Apart from the Ptychosperma macarthurii (Macarthur palms), we have a couple of palms that are apparently somewhat uncommon, and I'm trying to identify them. They've grown to about 6-8 metres, and are in a clump like the Macarthur palm, though they don't bend outwards in the same way.


The closest I can find is Dypsis lutescens, but even there the trunk is not yellow enough.


I also got some photos of the flowers, which attract bees



and the fruit which is a deep purple


Does anyone have any idea of what it is? Any help is welcome!

*Update 29/10/09*:
Thanks to the commenter anthrome below, and to the helpful people at Palm Talk, our palm tree is confirmed as a Euterpe olearcea aka Acai, apparently the palm hearts and berries are edible too! Gonna have to try that some time.