If designing for a site which has a significant audience in developing countries (Africa, Asia) where internet connections can be slow and technology used can be a bit out of date, is it advisable to use Flash? If not, what kind of technologies can be used to mimic the effects of Flash (eg roll overs) that don't require the visitor to download additional software?

As someone living in the Middle East where internet bandwidth should be more established than Africa, I would certainly recommend avoiding Flash!

80% of customers for one of the 2 ISPs over here are on 64k BROADBAND!? The internet is really expensive over here and the best broadband is 2MB. They have also not heard of contention ratios, so although we have a 1MB connection at home, loads of people are on the same pipe. As a result we get a fraction on the 1MB.

Keep it simple, pretend you are in the UK at least 5 years ago!