In reply to:

I do this from time to time - but I plead not guilty (too much) on the grounds that I tend to point out those with serendipitous linguistic felicities (or doubles entendres as the case may be).

I'm with shanks here. Another board that I frequent has occasionally had threads get badly bogged down by the Grammar Police. If it ends up being funny, however, I say, go for it. Of course, given the level of this board, if it's funny it was probably intended that way.