An item with the highest demand on the streets is a transit pass. When I volunteered to serve the homeless in central Phoenix, our restrictions indicated that we could only issue a transit pass for a documented physician's appointment or a job interview. Yes, after getting hired, they'd need to get their own transportation.
When I worked at a parish church, a certain donor often gave us a stack of transit passes, and we customarily gave them out, unconditionally and "no questions asked". However, this became problematic, and our pastor eventually decided to confront this issue along with the burgeoning litter in our spacious parking lot.
So he instructed me that anyone coming to the desk to request a transit pass, would first be issued a garbage bag, and we'd instruct them to go outside and gather rubbish until the bag was filled or time was up, and then they could trade that in for an authentic transit pass.
Ultimately, I think the end result was that demand for passes plummeted. "Word on the street" gets around really fast about these types of services, and so I think anyone in need of a transit pass decided to steer clear of our parish and find someone else to beg.