Unlocking a locked iPhone without iTunes or computer access

Hi all,

Sorry in advance for the umpteenth "locked out of my iPhone" question, but it's for my sister...

I understand from reading around that if I don't have access to a computer to restore my locked-out iPhone, I need to force the phone into recovery mode and then restore it. I've seen this URL quite a lot: http://support.apple.com/kb/HT1808

My question is that the how-to in that URL seems predicated on access to a computer/iTunes? Is there a step-by-step guide if you have no access to a computer or iTunes for restoring, or is that not possible? Losing all data is not a concern for me (it probably is for her, but my understanding is there's no way to do this without losing all data... I hope she's backed it up!)

Thanks in advance.