Electronic Service Signature Solutions?

LilJC asks: "I work at a company that does service work nationwide for a major chain. Our vendor requires a signature for every visit to every store. We have been running thus far from ICR on faxes and linking to the faxed signature image on our web site, but are having numerous problems trying to depend on a thousand+ faxes a month coming through perfectly. We are looking for an economical alternative that would allow a contractor in the field to get a signature and transmit it to us in an system I can idiot-proof. Something along the lines of the UPS guy's digital clipboard, but without the pricetag of a Telxon. Brainstorming myself, I wonder if there must be a cheap PDA/modem combo or the like that would allow a contractor to enter required visit information, get a store signature, go home, plug it into their phone line (without needing a computer), and hit send. I can code and am not afraid of doing some custom work for an app on a handheld. Does the Slashdot community know of any projects along these lines, or have ideas about a wise choice for hardware to homegrow the software on?"