your best bet is to find a hooker, make sure to toss her some money for her referral though, also check out http://www.webehigh.com but a lot of places don't have "designated" dealing spots like my city does
In old Vegas just keep walking up and down freemont. You'll see guys just hanging around. BUDS FIRST...CASH SECOND. if you look like a sucker you WILL get taken.