got a fantastic bit of kit and just wanted to share! i had to do a handful of 17hr flights recently, and wanted a backup battery for my Creative Zen MP4 player. it is dead handy for watching films etc, but even though the battery life is great (4hrs watching video) - obviously this would only do me for a quarter of the flight. so i was looking for an external battery / charger for it. i looked around for tech specs etc and did quite a search. in terms of size vs charge capacity, i was only realistically expecting to find something that gave me another four or five hours, to be honest. anyway, i bit the bullet and bought something called a Pines MP-530 battery pack. it costs Â£34.90 on Amazon and the link is here http://www.amazon.co.uk/dp/B0030434CE/?tag=armrumser-21 it fits in your pocket, has tons of adapters etc - all the kind of thing i expected. but what i did NOT expect was the performance. i plugged it in to my Zen and left it playing videos continuously - i wanted to see how much it extended the battery life. in the end, i had to re-start my test because it just kept going and going. so i charged it all up again and started over, listing every film it played and film length. impressive? well, the base battery life of the Zen is about 4 hrs. with this little gadger attached, the battery life increased to... wait for it... 23.5 hours!!! and that's not some manufacturers claim - that's me, playing it on constant video with full volume to see how long it would last. so - absolutely delighted with this bit of kit. i flew back the other day, 17hr flight, and when i landed it still had 60% charge left (wasn't watching vids constantly). i used to use a little charger that took 4 x AAA batteries, and for that flight i would go through the Zen internal battery, plus 3 sets of AAA batteries. not really one for posting reviews, recommendations etc - but this little thing has impressed the hell out of me. i would happily have paid double the price for it, if i'm honest. size, connectors etc - fine. battery life? fucking brilliant - "tick VG".