works now; here's what i did:
then i ran ifconfig an found wlan0 listed and "UP RUNNING" etc.

then
when it came up, it still didn't work; restarting my home router did the trick.

as always when i fix things in linux, i have no idea what the actual problem was, how i caused it in the first place, or exactly what i did to fix it. i know the following things:

-wlan0 wasn't listed under ifconfig; this should not be the case if the interface is up and running. i don't know how i took it down.
-when trying to connect, my home network was detected and (presumably) available.

if anyone can shed some light on this, it'd be great! thanks for the replies and suggestions, guys!

-steve