Log homes are typically "prepared" at a mill, with each piece faced, grooves, and jointed- all according to that vendor's particular design.
Corner joints are available with the squared dovetail, a half-moon, and even a copy of the "Lincoln Log" toy. Another design has the logs placed vertically, rather than laid flat.
One of the more common styles these days has a concave cut made on the 'bottom' side, with a lengthwise groove. The curve rests the log securely atop the one below, and the groove holds a felt gasket, to supplement the 'chinking' of log seams.
"Backwoods Home" magazine has regular articles, and publishes a number of books, on log home construction. Their authors have tried a variety of approaches to the electrical, and it's worth reading their works.
Personally, I'd run pipe as my first choice. Where they simply can't abide the sight, there's no reason you can't paint it "woodgrain," using milk paint and glaze. (AKA "Antiqueing")
