last time I looked I had no problem finding sources ... this time I can only find reports that they are working on extending the lifetime (which I suppose says it's currently short)
http://www.theinquirer.net/inquirer/news/659/1 038659/boffins-develop-long-life-flash
As I understand it flash memory has a useage life of about 10 years - but only a storage "shelf life" of about seven years max - before the capacitors start to reset.
good for lift and shift ... but not so good for long term storage
then of course there is the high rate of corruption - from �2 "bargains"
and impatient people ripping them out half way through a copy
compared with single session CD/DVD and HDD ... no contest
and of course the loss factor (if I had a penny for every one I've left plugged in or draged out of a pocket with my wallet .... well I'd be able to buy a replacement.
I use them all the time ... but only as transport.
a more loong term option is a microdrive
http://www.cclonline.com/product-info.asp?prod uct_id=9754&category_id=147&manufacturer_id=0& tid=zeus-4-cibox
single session CD/DVD are second best (at least for as long as they still make a device that will read them (remember betamax?))
but the storage that seems to last the longest is the all time favourite ... paper...
We have family photos going back to mid victorian which are a bit bashed about ... but still perfectly viewable.