For future reference, culled from [Peter Hosey][1] and [Ben Clark-Robinson][2], a mostly useful `.hgignore` definition for use with an [Xcode][xcode] project stored in the [Mercurial version control system][mercurial].

syntax: glob
*.pyc
.DS_Store
._*
*.xcodeproj/*.pbxuser
*.xcodeproj/*.perspective*
*.xcodeproj/*.mode*

syntax: regexp
^build/

*Ugh* to `.DS_Store` files and *gaaaaaah* to resource forks wedged into dot-underscore files. *Yay!* to regular expressions.

[1]: http://boredzo.org/blog/archives/2008-03-20/hgignore-for-mac-os-x-applications
[2]: http://mozketo.com/mercurial-hgignore-for-xcodecocoa/
[mercurial]: http://mercurial.selenic.com/
[xcode]: http://developer.apple.com/technologies/tools/xcode.html