Is it possible to order related entries by relevance of tags? I have a set of entries which each have 0 or more tags (no limit). For each entry, I am aiming to display 3 'related entries', related by the tags field.

e.g. If entry 1 is tagged with 'apples', 'bananas' and 'pears', then the first results returned would be entries with all 3 tags, followed by 2, followed by just one, then those with none of the tags.

Is this possible? I can't see anything in the documentation about ordering by relevance of the 'relatedTo' parameter.
I've made a plugin called Similar that does exactly this. Give it a go.