Me and DH have been married 2.5 years and together 10+ years but still don't have a joint account. We keep meaning to set one up but never get round to it. I think on my part because I'm worried about how it would work.
Being the main earner, all bills have always come out of my account and DH has put what he could afford (usually 50%) in my account. We would just randomly take it in turns to pay for groceries etc.... and I normally paid for holidays, splurges etc....
We now have DS, and DH is now the main bread winner-ish and I think we need to start thinking of our incomes being "Our" money. This isn't just because I am not earning as much but because I think it will be more relevant for paying for things for DS - at the moment I seem to end up being the one paying for the shopping when we need nappies, clothes, wipes etc....
My worry about a joint account is that we are both fairly frivolous spenders but while I keep an eye on what's in my account and always make sure I have enough in there to see us through the month, my DH doesn't have a clue what he has and often runs out halfway through. He has no idea how much and when his direct debits go out (drives me round the bend. I now keep track of those too). How do people keep track of what's in their joint accounts? I don't want to be stood at the till in tesco and find out that our account is empty.
It seems a bit pointless having a joint account, and an account each (for pocket money) but maybe thats the way forward? Or do I need to let go of control? Or should I just get DH to have all his wages put in my account and I give him pocket money? 
Sorry for the long post! TIA