It appears that my problems with my Powershot may not be the result of mishandling after all; I’m a victim of the dreaded E18 error. This appears to be a design flaw in Canon compact cameras that they refuse to acknowledge the existence of (the fact that there’s an extensive Wikipedia page for the problem says it all). Numerous solutions have been suggested; I’ve tried taking the camera apart a little to clean out around the lens but got nervous and screwed it back together again. My last attempt will be to buy some compressed air in a can and try that. By the sounds of things, if Canon try to charge for repairs, I may just have to pay up. But this, combined with the fact that it appears they won’t honour their warranties worldwide (which means I cannot really buy a 400D here) means that my opinion of Canon has plummeted from their previous record with me.
I’m still stuck with the problem of how to take pictures; I’ve looked into hiring a camera, but the only ones seemingly available are high-end SLRs at around $75/day - far more than I want to spend. I may just end up buying a cheap compact so I have some photos to take home.