One thing that puts people off when they consider building their own digital setting circles is the cost of the two rotary encoders that are needed. Building my DSC circuit is fairly inexpensive (maybe $30 or so), but a pair of high-resolution optical encoders can set you back to the tune of $150 or so. Recently, someone posted information about these capacitive encoders on the Palmastro Yahoo! group. Apparently, they work well in digital setting circles applications, and they appear to be electrically compatible with optical encoders. The spec sheet says they’re accurate to 15 arcmin, which is probably good enough for most users. The best part? You can have a pair for about $50. Digi-Key is supposedly a source of these babies.