OKC naturalization ceremonies are held at the federal courthouse @ 4th and Harvey in downtown OKC. Future dates for the oath and ceremony:
7/25
8/29
9/26
10/31
November-none scheduled
12/15

Thanks for that. I'd better add a bit more info for anyone involved at OKC --

I attended for interview at OKC Field Office on 19 June. The interviewer told me that they have beenholding extra ceremonies at that office as well as (or instead of?) the courthouse, as it's not big enough there. They held 3 ceremonies for 150 people in all last week.
She said they may do the same in July. I'm hoping to get a July ceremony, but am not counting on it.

N400 to TSC - 26 July 2007
PO confirmed signed for - 30 July 2007
Cheque cashed - 19 November 2007
NOA -Rec'd 26 Nov 2007 (Notice date 20 Nov)
PD - 27July 2007
FP -Notice received 6 December
FP Appt. 17 Dec. 2007
FP re-do appointment 22 January 2008
IL received 25 February 2008
Interview date 11 April 2008 1.05PM OKC
Interview postponed on day of attendance
New interview date 19 June 2008 - passed interview.

Interview notification "within 365 days"
Oklahoma City Field Office

I wished i had known there were people here from OKC or going to the OKC field office! That could have been very useful : )

I passed my interview on May 15th of this year and got naturalized just last week (June 25th). My Oath Ceremony took place at the immigration field office, in the lobby, with about 50 other people, plus their friends and families of course. So it wasn't at the Court House for us!

Hope you get your ceremony date real soon! Good luck to you!