Power Failure: Boot Camp Installation gone horribly wrong

Question

Was in the middle of the Windows installation part of the Boot Camp setup, and our building had a brief power failure. The Mac went dark. Upon reboot, it boots to a white screen but progresses no farther. The Windows XP install disk is still in the SuperDrive.
1. Partition was created successfully by Boot Camp Assistant
2. Windows installation had started, and was in the process of reformatting the partition to NTFS when the power failed.
3. iMac boots to white screen and stops.
I assume I need to get the WinXP disk out so I can boot from the OS X disk, but it isn't patently obvious how to do this without an OS interface. No hole to poke in a paperclip a la Windows drives.

Answer 1

Tried with no progress: still stuck at WSOD (white screen of death).
1) Booting with the Install Disk 1 in the SuperDrive while holding down the C key.
2) Booting while holding down the Command + Option + O + F keys
3) Booting while holding down the Command + Option + P + R keys
4) Booting while holding down the X key
5) Booting while holding down the Option key (this generates a non-functioning mouse pointer on the WSOD, which is more than anything else has done).
I have held down the keys in the following orders:
a) Before I push the power button
b) As soon as I push the power button
c) As soon as I hear the Mac chime
I have released the keys in the following orders:
a) As soon as the white screen appears following the chime.
b) Held for 60-90 seconds or more, with no change/response on the screen.
Unless someone else can offer another option, this is likely my next approach:
http://discussions.apple.com/thread.jspa?messageID=6498723&#6500810