I sent the tenant of my condo notice of my intent not to renew her lease last week - the lease ends in Oct 08 giving her the option of moving before Oct. by providing 30 days written notice and paying only rent for the last month she occupies the unit.

She responded with 30 days notice stating that she would vacate the unit by February 29.

Since she provided this date, can I hold her to this even though the least does not terminate until Oct 1 08?

Can I requires that keys be delivered to me by no later than 5 p.m. on the last day she occupies unit?

Please advise.

Yes and yes. You informed her that the lease would not be renewed and gave her the option of breaking the lease by vacating earlier provided she give you 30 days notice. She has given you that notice and given a vacate date. I would schedule a walk through with her for that date (or an earlier one) where she will turn over the keys.

She complied with your instructions. Just make arrangements for the post tenancy walk through of the unit and get your keys back then. I would change the locks anyway even it I got the keys back as you have no idea who else could have a key to this unit.