I did a quick check on both those two camcorders and the differences are small but you may still want to pay the extra for them. On the 860 it takes still pictures at 640 x 480 (not great but you could use them for email or put on a photo sharing website), composite video out, USB connection, apparently the 820 doesn't have a remote control included (I don't see one listed for it) and the 860 does have a remote control and the 860 does a built in memory, it didn't say how big it was.

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Better than a poke in the eye with a pointy stick any day...