very interesting stories - it's a different world out there, isn't it!
i prefer to think i live in a world where bribery and corruption are not tolerated - it's unethical, immoral, etc, etc.... but it's a nasty fact of life and it happens so it's important to know how to 'bribe' without getting yourself into more trouble so here's my input:
8 years ago in 'mid africa' i was getting ready to leave on the weekly departure flight. the locals had advised that the official manning the exit-stamp hut would require $10-20 to avoid "irregularities". But... if caught bribing officials, i could face greater penalties. in the back of my passport was a folded $20 note and i said nothing when i handed over my passport. my story would be "i didn't know that cash was in there.. it was a mistake" to blur any culpability. but when the passport was handed back to me, he smiled, i smiled back, i didn't look at the passport, and so.. left. once i was well beyond the hut, i looked into the passport and behold... no $20 note!
i believe the technique can be applied most times documents are required to be presented.