As others have mentioned, there are multiple pacman wrappers and/or alternate interfaces that include AUR functionality. AUR is really easy to handle for me and I almost never have problems using a somewhat popular package from there. If something is really esoteric, you may need to adjust the PKGBUILD, but typically stuff that doesn't have an actively maintained AUR install is obsolete anyway and won't build on newer versions of gcc.
I strongly recommend AUR and Arch. I use yaourt and I can update my AUR packages just as easily as I could if they were real packages -- just pass the --aur flag after -Syu (I also generally use --noconfirm, though this is dangerous and you shouldn't do it). Occasionally I use aurget to build a package if I know I will be using it a lot, because yaourt doesn't save the compiled project (it is saved in /tmp and deleted after the operation completes -- good for dependencies, bad for apps that you intend to modify or build often).