Modern app dev. For internal and Web application development, Java skills remain in high demand. "An increasing number of end user enterprise apps are written in Java," says Cushing Anderson, an IDC analyst. But Java skills alone won't cut it, he says: "You still need the structured back end. You need to be able to write in Oracle or SAP's development app."

But Java isn't the only hot app dev skill to have. In the last few years, there's been a surge in employers that assess candidates on their C# and ASP.Net skills. "From what we see, .Net is definitely hitting its stride," says Randy Kraemer, product manager for content strategy at Brainbench, a firm that does IT employee screening. "In the past, Unix, Linux, and Java had much higher rankings."

Kraemer also sees a big interest in anything related to Web 2.0. AJAX is an obvious hot spot, and Kraemer sees increasing importance of Ruby. These Web 2.0 technologies are in demand because "every site wants to have some sort of social interaction," he says.

Aside from the typical Microsoft and other vendor app dev certifications, IT developers should consider entering programming competitions such as those sponsored by Topcoder. "People who come off Topcoder with top positioning are likely to get offers of various kinds," says Diane Morello, a Gartner researcher.

The importance of multiple skills. Having an in-demand skill is certainly good for your career, but it's not enough for the long term. Companies are increasingly looking for cross-functional expertise. "The ability to make systems work together has become more important than ever before," says IDC's Anderson. "You can be a Cisco guy, but you'll be more valuable if you can optimize Cisco routing tables with your company's SAP financial applications. It shows you recognize how your piece fits in the broader circle of the organization." That might mean a combination of higher-level Cisco certifications with those of an SAP administrator. Unified communications and wireless obviously cross disciplines as well.

Crossing disciplines requires a firm expertise in the basics. "If you're a networking person who really understands connectivity, routing, and how networks really work, you'll be much more useful for a cross-disciplinary project than someone who knows just how to configure a specific router," says Global Knowledge's Walsh.

"We find that people are more likely than before to get several different certifications and that customers look at new technologies in an integrated fashion. You can't just know one area and not another," concurs Cisco's Beliveau-Dunn. That's why Cisco has started to embed security, wireless, and quality of service for voice in its CCNA, CCNP, and CCIE certifications in addition to offering speciality certifications for security, wireless, and voice. "Unlike five years ago, today, you have to start with all this on Day 1."