vimdiff and folding

vimdiff
do - Get changes from other window into the current window.
dp - Put the changes from current window into the other window.
]c - Jump to the next change.
[c - Jump to the previous change.
:diffupdate :diffu -> recalculate the diff, useful when after making several changes vim's isn't showing minimal changes anymore.

Folding
zo -> open fold.
zc -> close fold.
zr -> reducing folding level.
zm -> one more folding level, please.
zR -> Reduce completely the folding, I said!.
zM -> fold Most!.
:set noscrollbind -> temporarily disable simultaneous scrolling on both buffers, reenable by :set scrollbind and scrolling.

Reference

http://stackoverflow.com/questions/5288875/vimdiff-what-are-the-most-frequently-used-commands-shortcuts-that-could-get-a-n