Although Chicago’s unemployment rate recently fell to 5.4 percent from 6.6 percent a year ago, it is still higher than those of the nation’s other largest cities. The good news is that the job market here is heating up-at least if you’re counting Internet job listings. “There are more online job postings in Chicago now than there have been in the last three and a half years,” says Bob Plummer, an analyst at Corzen, a market research company that tracks hundreds of recruitment Web sites and online job boards, including the Big Three sites: Yahoo HotJobs, CareerBuilder, and Monster. In fact, local job listings on those sites jumped to 39,890 in April, up 26 percent from a year ago. Still, as Plummer notes, compared with other places, Chicago’s job market could benefit from even more heat.