We see people getting HELOC's frequently. Rates are very low right now. You do need to have good credit. You might also have better luck with a local bank or credit union than a national company. But if you still have equity in your home and good credit, you can get the line. The problem for many people is that the home will no longer appraise for the 80% loan to value ratio. They owe more in the primary mortgage than the house is worth! And 80% is about as far as most lenders will go. Back in the big loan days, we saw people who had HELOC's that went to 120% loan to value. That was just insane and the kind of thing that has contributed to this whole crisis!
A HELOC can be a good source of funds if you are relatively sure you can repay. Like any mortgage, you have to consider the fact you could lose your home if something happens and you default. HELOC's also make a good source of emergency funds - but you need to have it set up before the emergency happens. And they are not as good as cash in the bank!
The typical HELOC that I've seen has a 10 year draw. That means you can write checks, etc up to your credit limit for 10 years. During that time you have to re-pay at least the interest each month (although you could do that by drawing on the home equity line - we saw some financially ill advised people doing that!). After the 10 years, you either refinance into a new HELOC or there is a repayment period like a traditional mortgage. Most refinance into a new HELOC or a traditional mortgage that includes both the HELOC and the primary mortgage.