I came across a useful article on embedding fonts in PowerPoint (PC only, sadly not Mac yet). The author seems to imply it does work but I remain skeptical.
However, I am giving a talk next week and will be taking my presentation on a USB stick. I have written the talk using PowerPoint 2008 for Mac but will take it to my PC laptop running PowerPoint 2007 and see if I can embed the fonts.
But I will still be taking a default presentation which uses Arial just in case. I don’t want to be caught out again!