when i did the Mt Kinabalu trek in Malaysia a year and a half ago now, i approached sub contractors that worked for me and told them what i was doing. some obliged and gave me money. i guess i used my position within the company to my advantage, but i've never been unethical in my dealings and they were always above board. my company were aware of it. so you could use that approach.
i also approached Hilti - they produce power tools, and they offered me a hammer drill that i auctioned and made some good money there.
i made more than my quota so i gave some of the money i raised to another trekker who was having difficulty raising enough money for the same trek.
in saying that i initially did have a lot of trouble starting off, but in the end i stopped being polite when i asked people.
just out of curiosity, how much do you need to raise and what is the money going towards? its a good idea that you do some flyers so that people arent skeptical about your intentions. theres a lot of haters out there that tell you that ythey are paying for your holidays.
heres the thread to my trek to Mt Kinabalu
http://www.tfproject.org/tfp/general...13-2007-a.html