Not managed to get near the scales, but realised I had done so previously and posted the results on a different forum.
My 2 cell (7.4V) 2230mAh (got my maths wrong before - they come from a 4460mAh laptop battery) pack weighs 101g including (short) power cable, balance cable and fuse. On that basis a similar 11.1V 2230mAh pack would weigh only ~152g. Beat that with a LiPo!
I'm sure TaskLED will be back shortly - according to Ifor he's just away for a month. Since I was already using low voltage cutoff with NiMH cells and my custom LVR when I went to LiIon, I've never felt the need for a separate protection circuit, and hence always happily used bare LiIon cells from ebay laptop batteries. Was one of the principle reasons I developed custom bFlex/Maxflex firmware, since at the time there was no low voltage cutoff in the stock firmware.