Alright, Here is a tip I was recently just told that I think is just fantastic. I buy celery about once a month. We don't usually eat it raw, except in salads. But I always need it for different recipes. By the end of the month my celery is usually limp. Because I don't like to throw things away I go ahead and use it anyway. But then my buddy Janette told me that if I wrap my celery in Aluminum foil it will keep crisp for a lot longer. Voila. It works. Now I'm sure there are probably other great ways to keep your celery fresher but... I don't know them.
Check out Tammy's recipes for other great tips.