We were shown 3 types of knot at ASOB Briefing....does anyone know for sure if any knot-work is req'd or deemed necessary at MB?

Perhaps during command tasks?

I seem to remember breathing through my balloon knot on the assault course and final race, but that's about it!

If you can't remember them it's really no biggy. Someone in your team will be able to, so just utilise them. You'll get just as many marks for that as doing it yourself..
I would recommend the following:

1. Reef knot – to join two ropes together.
2. Bowline – to fasten a rope to a strong point.
3. Clove hitch – to fasten a rope to a pole (or such like) quickly and you can easily lengthen or shorten the rope.
4. Figure of eight and on the bite – used as a stopper knot (never tie an overhand knot otherwise known as a thumb knot), or to put a loop in the rope.
5. Highwayman’s hitch – has two useful features, first, once tied onto a strong point it has a load bearing end, and a quick tug of the other end releases the rope. Secondly, the knot is tied using a bite so you can tie it and release it without having an end.

With just these 5 knots you can do almost everything.
Each knot is easy to undo even if a lot of force has been put on them.
I would simplify FF's advice. You really only need to know two types of knot.

1. The figure-of-eight.
2. The bow

The second is used to tie your laces and bow-tie. The first for just about everything else.

If you bother learning any type of knot, make it these.
The nuances of knots are a skill well worth knowing for many reasons.

How on earth could a chap restrain his lady at the proper time without such knowledge? Basic knowledge!
The briefing is an insight to the main board so given they show you a few knots it's pretty safe to say you may need them at the main board.

You do need to do them quickly and they will stop you if you're using the wrong knot, however we mainly only used a reef knot, it just depends on which command tasks you get.
Used the clove hitch to put two planks together to impressed mutterings from the board staff! Just learn them and they might come in useful on the command tasks. Reasonable amount of ropes involved depending on the tasks set so can't go wrong.
craftsmanx said:
As an ex Stafford I can tell you that there is only one knot and that's worn on the Berets of The Staffordshire regiment (The Prince of Wales's)
Very, very long shot here...

Were you in Harry's bar in Changi Airport early January 2007? Only asking because I met an ex-Stafford there.