Thanks to all who've posted.
I didn't mean to imply that I don't plan to change my eating habits (which obviously suck) but rather that I don't want something as strict and regimented as the Zone. I realize, both from other's anectodal experiences as well as my own, that diet is the major factor I need to focus on. For now, I figure to just incorporate healthier food choices with moderating caloric intake. I know for myself that at this size that is sufficient to lose weight. As my weight comes down and my fitness levels rise I think really dialing in some sort of dietary plan will become more of a priority.
I think the advice on walking is great. This weekend we signed a purchase agreement to build a house and the really good news is that the lot next door is part of the community's "common area" and more importantly one of the entrances to the community-wide walking path. My fiance has been after me to start walking for some time and I think she just effectively removed any excuses.