Yaourt (Yet AnOther User Repository Tool) is a community-contributed wrapper for pacman.
Ranked in these QuestionsQuestion Ranking
Pro Equivalent to pacman
Yaourt commands and flags match pacman, so it is immediately obvious how to use it.
Pro Adds seamless access to the AUR.
Pro Colored output
Pro Can be set up upgrade your system with no additional prompts
Pro Supports backups
Con Does not perform clean builds
Environment variables may get carried over while building a package, preventing successful building.
Con Breaks when updating AUR packages as root
Does not gracefully drop permissions when executing makepkg, which fails when running as root.