I'd use it and pay it off before statement date.
Chase posts statements on the same date every month (always the 5th, or the 19th, or the 24th, or whatever you have going on.)
Buy a tank of gas a couple weeks before the statement date, and pay it off online when it shows up the next day or two. Then put the card back in the sock drawer. Chase is happy (you're using the card), FICO is happy (you're using the card + you have a string of $0 balances), and your car and gas station are presumably happy, too.
Dunno what it takes to get a better APR from Chase. I was all excited that when they closed the Borders VISA program, they switched my card to a Freedom. I was happily calculating my top three categories when I found that my card has some sort of lame-o Ultimate Rewards program, which is decidedly non-ultimate (point per dollar.) The Borders card had better rewards than that.
I'm not going to say anything to them until they soft me again and have the new reports without the J.Crew 90-day. Maybe they'll perk up then.
* Credit is a wonderful servant, but a terrible master. * Who's the boss --you or your credit?
FICO's: EQ 781 - TU 793 - EX 779 (from PSECU) - Done credit hunting; having fun with credit gardening. - EQ 590 on 5/14/2007