I know I can access voltage drop calculators on websites (like Vista's) or download the Unique Wiring Wizard, but I want something I can take to the field with me when measurements on paper are different than what I find on the ground, or plans change. I'm basically looking for something I can use for those on-the-fly, work in progress design changes, where I know my distances and number of fixtures I want, but don't have Internet access or a laptop with me. Basically I want a hand-held calculator into which I can change variables, like Watts, wire gauge or length of run to see which will work best for me. It could be standalone (my preference) or even a program I could run on a Palm device or smart phone. If it would also allow me to enter my costs for various materials and help come up with and compare the results of different wiring methods it would be even better. Calculated Industries makes the Electricalc. http://www.calculated.com/productcart/pc/viewPrd.asp?idcategory=0&idproduct=160 Many more functions than I would ever use, and nothing aimed at LV lighting as far as I can tell. I talked to someone in R and D there, and he didn't think there was a big enough market to make it worth their while.