The news seemed so lovely, so sudden, so decisive: effective tomorrow first thing, Starbucks Corporation (NASDAQ:SBUX) stores in my hometown, Portland, and in several other major cities (including Seattle, San Francisco, and New York) will replace all trans-fat loaded treats with versions that are free of the artery-clogging stuff.

You'd think I'd be happy. After all, I'm the one who rails on companies for using trans-fats in their foodstuffs, and examines grocery store labels so carefully I did a whole photo essay on it. And both I and my adorable, sugar-crazed kids are frequently found at our local Starbucks, eating the chain's doughnuts, its Cranberry Bliss Bars, its glazed, colorful cookies.

But here's the thing: I didn't realize Starbucks treats had any trans-fats! In announcing this proactive and kind move, Starbucks shook the very foundation of my blissful ignorance. Heading immediately over to Starbucks' web site, I pull up the nutrition information for my local store (since treats are baked locally and different stores have different offerings, each "zone" has its own nutrition sheet). And I am floored.

For nearly 10 years now, I've been fiercely guarding my shopping cart. The wicked would-be interloper: partially hydrogenated vegetable oils, also known as trans fats or trans fatty acids. And it's in everything, from wheat bread to soup to my favorite sticky candy bars. For a while, I was a lone voice and a lone label-reader, inspecting in the wilderness of my grocery store aisles without another soul to fight against the cheap, shelf-stable, yet bad-for-your-heart fat.

In the past few years, a growing public backlash against the stuff, known to contribute to heart disease and obesity, has led to its removal from many major products, from Lay's chips to sandwich cookies. Most Trader Joe's products are now free of the substance (and thus, it's my favorite place to shop). And then, this month, came the New York City ban: no restaurants will be permitted to use trans-fatty acids in cooking oils come July, 2007 -- and trans fats will be banned entirely from all foods available in restaurants by July 2008. This week the Washington State Board of Health announced it was considering a similar ban throughout the northwestern state.

Should you join me and New York City's best (and not-so-best) restaurants? Should you ban trans-fatty acids from your pantry, too? I looked at a bunch of products in my local grocery store to evaluate whether they were worth banning and whether or not my budget could manage it.