As an award-winning* baker with a degree in Biology, I'm particularly keen on accurate measuerments and weights.  While much of cooking is an art, some of it — especially baking — is a science.  And if you do a lot of it, you really need to accurately measure your ingredients, particuarly things like flour.  The current issue of Cooks Illustrated features a test of 18 cooks and non-cooks checking the variance in flour and water measurements using dry and liquid measuring cups.  Not surprisingly, the variances were large.  Measuring a cup of flour using a Dry measuring cup resulted in a arience of up to 13 percent, and using a liquid cup, up to 26 percent.  While most recipies list flour in cups, the amount in your cup depends on how heavily packed it is.  A cup of flour should weigh 5 ounces.  That's where a good scale comes in.  OXO Good Grips Stainless Food Scale doubles duty as a postal scale (up to 11 lbs.), and has a couple of really great features, most notably: a pull-out control panel, that lets you see the display that might otherwise be hidden under a large bowl or pan, and zero out the weight, so that you can sequentially measure and add ingredients. It's $49.95 with free shipping from amazon.com.  (Cook's Illustrated's previous top choice, and less-expensive option: The Soehnle Digital Kitchen Scale, $30.78 with free shipping at amazon.com.)

*I've won the Water Island annual pie contest, twice, with my Banana Cream Pie. That recipe is a little involved, but for a quick and easy summer treat, here's my secret for the best Key Lime Pie.