Well, I am very fond of frozen mangetouts. Pour boiling water over them, drain before boiling, chill in cold water, and instantly into packets in the freezer. I am very pleased to come across them in mid-winter. I thaw them, pour boiling water over them and drain before they come back to the boil, and I find they still have a pleasing crunch and a lovely fresh flavour. If I am podding some "ordinary" peas, I add some of them as well - it is a good mixture. Adding a spare outer lettuce leaf to a pan of boiling water before adding the thawed peas gives a pleasant flavour, too.
I agree that runner beans are not worth freezing, and that if you have to, they are best used to bulk out a casserole of some sort. I like french beans frozen, though.