Although quite thick (0.3mm) and limited flexibility, I thought it worth trying to use it with knitting or crochet. The EL wire is not flexible enough to knit with. I tried 3mm, 4mm, 5mm and 6mm needles, and just ended up with blistered fingered and snapped EL wire.
This hat was on my stand at Maker Faire (Newcastle) and Mini Maker Faire (Brighton) in 2013. It was very popular, though many commented on how heavy it was, but how useful the battery pack is.