Your imagination is the limit.

Perhaps on the balance sheet of another company.
Usually on the balance sheet of a Special Purpose Entity (SPE).
Your company's shareholders perhaps know it, perhaps not.

do you mean "creative accounting"?
I prefer to call it "financial engineering".

Debt to GDP ratios be damned (assuming the debt is used to return the economy to a normal level of activity)

Normally I would agree but:

1. Much of the downturn was caused by unsustainable asset and cost inflation.  Assets have imploded.  Costs are only v. slowly returning to "normal"=sustainable levels.

2. There comes a point at which huge budget deficits become self-reinforcing and unsustainable because the cost of borrowing goes up even more than the rate of borrowing because foreign lenders simply won't lend without increasing risk premia.  Irish public and private foreign debt is c. 800% GDP, so we are huge over-leveraged as it is.

3.  Most of the down turn has been in the construction and tourism sectors.  Construction was c. 15% of GDP (if memory serves) and we were building houses at a rate c. 50% the level fro all of the UK.  Not only are many of those houses empty, office and factory vacant space is at record levels.  It is pointless trying to reflate that bubble just yet.