Interesting article about Micro-O in the most recent issue of O-Sport. Part way through a race participants have a 1 to 1.5 km part of the course with 4 to 5 televised controls. There is no code on the description sheet. In the terrain there are a number of controls (only one is the correct one) within the cirlce of each of the 4 to 5 controls. If a person mis-punches then they have to run penalty loops (like biathlon) when returning to the finish arena. I recall the Colorado 5-day (back when it was in CO and <1K days long) having a control on all boulders in some forest late in a sprint race. That was when sprint wasn't a WOC race and micro-O wasn't even heard of in Sweden. SwampFox is such a trend setter.
I tried something similar in a park meet a few years ago. I called the meet "Grab a Clue." At each control circle (circles were about 100m across, and the control could be anywhere in the circle) you had to use the clue to figure out which of 4 or 5 controls to punch. Scoring was based on the number of correct punches with time as a tie-breaker.
The format worked well except for one hitch. The Wickens were having some sort of gathering in the park that day as well. The park ranger wasn't too happy about the public perception of a bunch of witches running around the park so he told them they had to limit their activities to the section they had reserved. When he was driving around that morning and saw wooden control stakes all around the park, he throught they were bustin' the rules and pulled them up. He pulled up four or five control sites before he realized that they were orienteering markers. A rare case of an O-meet suffering religious persecution.