A little poking around revealed that this file /usr/share/doc/wpasupplicant/README.Debian.gz was the secret sauce for getting wpasupplicant painlessly functioning on a Debian machine.
Like with wireless-tools, Debian has integrated wpasupplicant into the /etc/network/interfaces file.
To talk to a simple WEP-encrypted access point, this is the stanza I am using in /etc/network/interfaces:
auto eth1 iface eth1 inet dhcp wpa-ssid linksys wpa-key-mgmt NONE wpa-wep-key0 8453017892 wpa-wep-tx-keyidx 0
To achieve the same with wireless-tools instead, I have this stanza:
iface home inet dhcp wireless-channel 11 wireless-mode managed wireless-key 8453017892 wireless-essid linksys
and of course, "ifup eth1" and "ifup eth1=home" will both connect, the former using wpasupplicant and the latter using wireless-tools.
Of course, the whole point of wpasupplicant is to talk to a WPA-encrypted access point. Stay tuned until I get a chance to try it again....