I know several guys who have done this. At almost any airline I think that if you leave in good standing and explain why you are leaving, they will hire you back at the first opportunity. There are several good reasons for them to do this. But if you actually resigned, you will be starting all over at the bottom, not "sliding back in" where you were before. You will need a reasonable hardship explanation, not involving another aviation job offer.

But like others said, try to take a LOA, that way you will keep your accumultaed seniority and longevity. You will not accrue any more while you are gone though (unless it is military leave).