The quality of articles in Wikipedia has grown tremendously in the last few years. A "good article" requires a big list of necessities, including coherence, readability, comprehensiveness and credible references. As such contributing technical articles requires academic merit, good explaining skills and mastery of the subject.
- How much value is being accorded to doctorates' contributions to Wikipedia during faculty recruitment?
- Since, on paper, a Wikipedia article should exposit an article lucidly to a (relative) fresher in the field, can Wikipedia contributions be taken as a partial measure of one's teaching abilities?
- How effectively could one list his/her Wikipedia contributions?
I have never heard of any weight given to contributing to Wikipedia for any aspects of academic evaluation. I personally wouldn't attach any weight to it either, especially given that many articles have a long history of edits and figuring out exactly who contributed what can be difficult.
If you want to include this on your CV or similar, I would mention it under "Misc." or "Other" or something like that. If you have made significant contributions to other similar sites (e.g. stackoverflow) I would put that into the same paragraph. I would definitely avoid trying to make it appear as one of the major things you have done. Wikipedia is regarded rather suspiciously in general because it can be an unreliable source. While contributing to it could be a bonus, it won't be a significant one.