I really appreciate the responses.

Fostering sounds like the way to go. That way I can avoid a commitment until I'm 100% certain. And it would be so helpful, too.

One question though - what about vaccinations and medications? Wouldn't it be just horrible for a foster dog to contract lime disease or heartwormm while I was caring for it? Do you think the vets give discounts to people who are fostering? I love dogs, but I don't have the $ to vaccinate many of them.