Thanks to the Arch Wiki, I've managed to figure out how to scan for wireless networks, connect to one, and get an IP address on my Arch box.

Since I connect to the router at home most of the time, I wrote a short script I can run from a panel launcher to connect to it.

This leaves me with a few questions though.

First, how does one disconnect from a terminal, and put it in a state ready to scan for a network again?

Second, is there any way to have my script get called during boot up, rather than after logging in? I can move it to a more suitable location than my home folder if necessary.

And third, if I've connected via command line like this, what ways are to obtain statistics such as signal strength, noise and so on? Can Conky be configured to show this information?

Thanks in advance.

Have you discovered the man pages for iwconfig & friends?
Read up on them. To your wuestions
1. Have you tried ifconfig wlan0 down?
2. Call your script from /etc/rc.d/~/rc.local.
3. Iwconfig's friend iwlist gives those details, and there are no doubt other ways.

With a little look into those man pages, I've solved the first and last, at least.
I'm not entirely certain how /etc/rc.local works - do I just add a line that runs the script, something like this:

I don't think you need the 'sh'. Here's the rc.local from this old box
bash-3.1$ cat /etc/rc.d/rc.local
#!/bin/sh
#
# /etc/rc.d/rc.local: Local system initialization script.
#
# Put any local startup commands in here. Also, if you have
# anything that needs to be run at shutdown time you can
# make an /etc/rc.d/rc.local_shutdown script and put those
# commands in there.

/usr/bin/inadyn --input_file /etc/inadyn.conf --background