bletcherous = B = blinkenlights
To use a navigator or off-line message reader to minimize time spent on-line to a commercial network service (a necessity in many places outside the U.S. where the telecoms monopolies charge per-minute for local calls). This term attained wide use in the UK, but is rare or unknown in the US.
--The Jargon File version 4.3.1, ed. ESR, this entry manually entered by rootbeer277.