[caseymarquis]

'[d|c]iw', to delete/change the word your inside of is another small improvement.

[_frog]

I'm also a big fan of `ci[(|'|"]` to change all the text between a pair of delimiters. I can type `ci"` while my cursor's at the start of the line, and it'll jump to the first set of double quotes, remove the text that's currently between them, and enter edit mode.

[the_white_oak]

You can also use `cib` to change text between braces and `ciB` to change text between curly braces.

[LyndsySimon]

Isn't this part of vim-surround?

http://github.com/tpope/vim-surround

[mercer]

I'm fairly sure that works out of the box. I get annoyed when another editor's VIM mode doesn't properly emulate it.