The next Slackware release (12.2) will have a network manager like in other Linux distribution. This package is called wicd and it's not yet put on the main directories, so you will have to install it via /extra directory. Please read the README.SLACKWARE if you want to install it on your machine as you *may* need to tweak some configuration in /etc/rc.d/rc.inet1.conf.
Here's some feature in the wicd packages (taken from the original website):
1. No Gnome dependencies (although it does require GTK), so it is easy to use in XFCE, Fluxbox, Openbox, Enlightenment, etc.
2. Ability to connect to wired and wireless networks
3. Profiles for each wireless network and wired network
4. Many encryption schemes, some of which include WEP/WPA/WPA2 (and you can add your own)
5. Remains compatible with wireless-tools
6. Tray icon showing network activity and signal strength