I like these hypotheses that are worth trying on before you make a debt-incurring decision - they're like some of the features of a “debt lifestyle mentality”:

o We NEED more than God has given us
o God doesn’t know best what our NEEDS are
o God has failed to provide for us, forcing us to take matters into our own hands
o If God doesn’t come through the way we think he should we can find another way
o Just because today’s income is sufficient to meet our debts payments, tomorrow’s will be too
o Our circumstances won’t change, our health will be good, we’ll keep our job, we won’t have a baby…God won’t lead us to a lower paid job or to increase our giving

These make me think harder about going into debt...

Wise Money, http://www.wisemoney.co.nz/
has some good resources about managing your money. I suspect you might have already been to the seminar?

They talk about turning the "standard" model of payment up side down. Most people do this:
First pay fixed costs,
Second pay incidental costs
Third Save
Forth Give away the "Excess"

Phil Strong says it should be the other way around (I'm not sure I totally agree but it is an interesting perspective). We should give first, then save some thing for later, then pay out incidental costs and finally pay our fixed costs. The real benefit of this model is that we then have to focus on reducing our fixed and incidental costs rather than going "Ooops, I didn't have any money to give or save thing month".

Another tool wisemoney suggests is getting your planned "incidental spending" money out in cash straight after each pay packet. Then you use that money and only that money on incidental spending. Once it is all gone and you want to go out for a coffee, you can't the incidental spending budget has been spent! This should help you quickly understand where that incidental money is going :)

Hmmm Money, I just can't stop...

You said Visa interest is a trap, I would take the as far as to say all interest paid on something that isn't making you more money is a trap.

That means that interest paid on a hire purchases, bank overdrafts, personal loans etc. are all traps. They just eat your money.

The only time it is ok to pay interest is when the thing you buy makes/saves you more money. For example buying a house generally involves a mortgage (and therefore interest) but it will either be saving you the money you are paying in rent, or earning you income by having it rented out. In that situation it is usually (often?) worth paying the interest.

Another time this might be the case is if you need to have a car to get to work. This fits the requirement of making you money, because if you didn't have the car you couldn't go to work => you couldn't earn any money. BTW: I think this case is incredibly rare, don't use it as an excuse to borrow money on a car.