We have our own checking accounts where our money gets deposited and from there it gets moved mostly to our savings at ING direct... Now capital one 360 grrrr...
If I want something I buy it. If she wants something she buys it. If it's a big ticket item we will normally talk about if we need it or not but $500 or under meh. Whatever. As long as we have money going into the savings monthly I could care less.
Our savings is a joint account we can both pull funds or add funds. Both normal savings and a business savings for one day starting something. I trust my wife, If she wanted to she could go buy a brand new GTR in cash... But I trust her