Bike attack!

Ive been in a few 'dodgy' situations, out late at night, in the wrong part of town, ive even been attacked once (it was over pretty fast as the ticket inspector in Croatia jumped the guy attacking me)

But ive never been in a mugging/armed robbery situation, and id love some advice or experiance shared.
Not the happyest of topics, but its a valid one that people should be prepared for at least.
Do you hold your ground, do you obey, at what point would you say no, what attitude is respected and what causes further insult???

In 1 month a group of us are planning to cycle from the UK to Kenya, ( www.downrightkenya.org) round through Turkey, into africa through Cairo, Sudan, Ethiopia, and Kenya. Now one of my main worries is not so much the fear of loosing all my stuff, but how to best deal with a situation, where we as a group would be truly vulnerable (im with two girls) , on the road in the country, and how best to deal with the 'bandits' so we come out ok.

Im not expecting attacks around every corner, but I know a lot of people out there will have some good stories with helpful outcomes, if so, please write a little of the situation and what you found helped.

Happy (and safe) travels all.

Mark