overview of Arch?
 

Alright...slap me if you want, but please tell before it, how you shortly describe the good/bad sides of Arch, and why would/wouldn't you use it?

:) I'd like to hear about these things:

- what it needs from a PC (laptop?) it runs on?
- how do you get apps in it (package manager/compile/magic)?
- installation: easy, hard or impossible (the last choise doesn't exist, really ;) hehe)?
- usage: how difficult is it to learn to use it?
- support: are there any things it doesn't support/can't use etc. that others do (some devices, for example)?

You can tell plain facts, which I hope to hear, because I'm only looking this for a friend of mine...myself I've been satisfied with Gentoo (but what keeps me from being interested in Arch?) but I got a call to search for a nice distro for a almost-beginner's somehow old (400Mhz) laptop.

BIG thanks for answer(s)! :)

Arch is outstanding for several reasons:

1) It is optimized for i686 architecture (and therefore v.fast)
2) Arch's packet manager is very solid (It automatically resolves dependencies, and helps you keep on top of security advisories)
3) Installation is quick and easy. (Less than 20 min for the base package)
IMHO, it is a very polished distro, I definitely recommend it.

Re: overview of Arch?
 

A i686 processor (pentium II or above). To install you also need a CD-rom or floppy-drive+ethernet.
Binary packages are handled by the package manager pacman. Pacman can handle package installs, dependencies, uninstalls (normal and recursive), and upgrades (a single command updates the system).

Customised packages - or applications that aren't available in the Arch respitiories - can quite easily be built from source using ABS (Arch Build System). These packages can then be installed/uninstalled with pacman.
The installation is ncurses based. You need to understand partitioning and how to edit a few files:
/etc/fstab
/boot/grub/menu.lst or /etc/lilo.conf
rc.conf (this is a global arch config file, it's used to select timezone and keymap, setup network, select wich modules to load and which daemons to start at boot)

If you want X you must create a XF86Config somehow as well (next relase of Xfree86 should have auto-configuration, but thats still in the future).

I recommend reading the installation HOW-TO to get a better picture.

Well, it's linux plain and simple. For a complete noob there will - as always - be some learning to do. Point-and-click system administration apps are few and far between. However there is little actual system management to do once everything is configured, running pacman -Syu once in a while to update the system will be quite enough..
Apps that are specifically written to work with RedHat or another linux distro might not work, fortunatly those are pretty few. As for devices Arch support == support in kernel. Almost everything is available as modules in the stock kernel. If you miss something you can roll your own during install or later... If you need commercial drivers you will have to get them from the vendors.
I like Arch and I was an near newbie when I first tried it and got hooked. It wont hurt to try ;)

A few links:
Arch homepage
Review at OSnews.com
Distrowatch interview with the creator of Arch

Hmm...that does sound good :) besides, editing some config files or playing around with kernel changes is no problem. Now, if I'd like to get Arch, how would I do it? I suppose getting some iso-image from Arch's website is the way (as usually)? How big is this (the smaller, the better..)?

A million thanks for quite a complete answer(s) to my question(s)...indeed.

You can get Arch from any of these mirrors http://www.archlinux.org/download.php. I usually download the base ISO image (about a 106M download) and choose the FTP install. This ensures your system is installed with the most up-to-date packages in the Arch repos. During the install you will be prompted to select Packages, I suggest choosing the base package group to get a working system configured. Once you have booted into the new system you can then run Pacman to download the rest of the applications you want.

Another benefit of Arch is that the install is very quick and you will have a usable machine in less then 25 minutes (15 after you have gone through the install a couple of times). This is one of the main reasons I switched to it from Gentoo. I didn't like waiting several days to get a working system.