Have you switched to CF bulbs? I've been seeing them for really cheap lately. I picked up 4 GE branded 100W equivalents for $7 at Rite-Aid of all places the other day.
Also, this may be an impossible task with your spouse. Having lived with a roommate who wouldn't turn lights off, I've found that if it wasn't drilled into you at an early age (my father was a nut about energy conservation back when it was still underground) it may be a lost cause.
Yeah, we used CFLs in our old house, but when we moved here we were a little slow in making the changeover. I figured we'd wait 'til the incandescents burned out and change them one by one as needed, but after our first electric bill, I went through and changed them all. Our first full-month bill was $227, out second was $135 (after I changed out half the bulbs), and our latest bill (which I just got) is $108. Meanwhile, our gas bill (we have gas heat) has only gone up $10. So, yay.
There's still the issue of "why can't you do this for me just because I asked you to," but that's a whole different problem for another time.
Anyway, as those of you on Facebook know, today I'm gonna send a secret something to a secret someone.