As our financial situation improves, I've decided that there's no need for us to have an "emergency" fund.
We build funds for future known expenses (insurance, vacation, etc.), have mini-funds for unknowns (house maint., car maint., medical), plus a 1 month income buffer. Those are all kept in checking, which fluctuates from $7k-$10k. In addition, I have a small rental-maint. fund and a new car fund in a SmartyPig account. So currently have access to around $20k cash, plus I have over $50k in available credit, plus whatever credit my wife has.
In addition to having access to plenty of funds, as someone else mentioned, if your free cash flow is good you can cover quite a bit with that.