Any “Memory stick duo”. Sony, or other brand. Size – depends what you want it for, for a few stills doesn’t need to be very big. Something like
http://www.amazon.co.uk/exec/obidos/...178173-6535111
If you go non-Sony, look on ebay you can get cheaper ones.
The “MagicGate” ones can be used to download certain copyrighted media… this isn’t of use with the camcorder. They will still work to hold your photos or video clips (just can't play downloaded files with MagicGate copy protection).
You only need an adapter if you want to use the “duo” (small) stick in a device which takes the old (larger) sticks. Your camcorder should have come with one.
Mark