I don't know, if people are completely ignorant to anything Powerpoint related they're decent prices, but anyone who can run the Powerpoint wizard will probably think twice before hiring you.
Unless you've got a lot of experience with marketing, people probably will find it experience. But that shouldn't stop you from trying, though. Perhaps you'll get a lucky break. Try contacting stores, because they will want new presentations for products on sale.. And perhaps busy salesmen who need to present things but haven't got the time to build a presentation themselves.