Boneson keeps complaining that all the music stands in our house are too short to stand and play at properly and I am reluctantly beginning to agree. I've done a quick internet search and the only ones I've found so far are the fairly lightweight looking fold-down ones which I generally find great for carrying around with me for sitting down and orchestral playing but I'm not sure how stable they would be when fully extended, loaded with music (and possibly the odd folder) and in close proximity to at least one, if not more, lanky, energetic, teenage jazz trombonists.
Does anyone have any experience or suggestions for taller music stands - and what does and doesn't work?

Maybe you can find what you are looking for on this website:

K&M Music stands

Unfortunatly I don't know where you can buy them in Great Britain.

You can get some quite sturdy ones if you're content for them to not fold down, i.e. for use at home only. There are some gorgeous wooden ones available that might go high enough, and also some slightly more lightweight metal ones. You may have seen these - the bit for holding the music tends to be one solid, flat piece of metal. Try typing "symphony music stand" into your search engine.

As you say, the lightweight fold-away ones are great for taking around and for playing whilst sitting down, but it is really important that if he practises standing up that he isn't using a stand that is a foot too short for him. It will eventually cause him pain and certainly won't do anything for his playing.

I use one of tese

http://www.amazon.co.uk/Technote-G905-Cond...960&sr=1-10

I find it very sturdy. Te base and pole are adjustable and te top is a one piece plate tat tilts. It's sturdy enough to support a perspex mirror.

Sorry - my letter aitch seems to be broken.

You could try the RAT Jazz stand, which has the benefit of a sturdy desk and also folds down (the leg telescopes) so it can be used outside of the home as well. I had one for Christmas to supplement my permanent RAT stand in the music room and my lightweight portable RAT stand I use for events where I need a small collapsible stand.

The full range can be seen here. I own the Jazz stand, the Scherzo and the Performer stands and would recommend them.

I bought one of these (Konig & Meyer extra tall folding stand) last year:

http://www.justflutes.com/pages/product-detail51262.htm

It's pretty stable in practice, despite being a folding variety, and the height is infinitely more comfortable than the norm.

We have both of these types at school, and they're generally quite sturdy, and go up pretty high too. I would personally recommend the jazz stands because the other ones at school are falling apart a bit ( but that might be after several years of being dropped and broken by teenagers) and also the jazz stands are equally as sturdy, only they're lighter and fold flat.