Working in IT isn't always pretty. After all, we can't all work on the cutting-edge technologies all the time. Some of us have to get dirty—in some cases, literally.

Unfortunately, dirty jobs—whether you're being chained to a help desk, hacking 30-year-old code, finding yourself wedged between warring factions in the conference room, or mucking about in human effluvia—are necessary to make nearly every organization tick. (Well, maybe not the human effluvia part.)

The good news? Master at least one of them, and you're pretty much guaranteed a job with somebody. We don't guarantee you'll like it, though.

Here are seven of the dirtiest jobs in IT, and why your organization needs them.

Dirty IT job No. 7: Legacy systems archaeologist

WANTED: INDIVIDUALS FAMILIAR WITH 3270, VAX/VMS, COBOL, AS/400, AND OTHER LEGACY SYSTEMS NO ONE ELSE REMEMBERS. MUST BE ABLE TO TYPE ENTIRELY IN CAPITAL LETTERS FOR EXTENDED PERIODS. APPLICANTS MUST MEET MINIMUM AGE REQUIREMENT OF 55.

Believe it or not, COBOL developers are still in demand, says Jim Lanzalotto, vice president of Yoh, a technology talent and outsourcing firm. "I'm looking at a job listing right now for a PeopleSoft business analyst," says Lazalotto. "Buried in the middle of the description, it says, 'writes COBOL as needed.' Here's another one, for a senior program analyst with a background in IBM WebSphere, EDI, Unix, and secure file transfer protocol—'knowledge of COBOL a plus.' Imagine your average 29-year-old hipster applying for one of these jobs. 'You want me to know what?'"

You'd think these old systems would have died off years ago, but larger companies—especially in financial services, manufacturing, retail, and health care—cling to them like drunken sailors to a lamppost.

"I know of at least one major office supply retailer that powers its site by connecting AS400s to Web front ends," says Andrew Gelina, CEO of Syrinx Consulting, in Waltham, Mass. "The cost of rewriting or migrating these apps is huge and the risk is high, so they look for any way possible to reuse and reconnect to modern technologies. It's like marine archeology. You'll need a spelunker to dive deep into them, figure out how they can be bolted and duct-taped into a more modern integration engine, like a SOAP/XML front end."

The good news? Experienced techs willing to do these dirty jobs may discover reliable income streams as they ease into semi-retirement.

"There's an interesting inversion principle at work here," Gelina says. "The value of people with skills built around those systems had been going steadily down for a long time. Now that companies can't find anyone to work on them, the reverse is true. If you're a consultant who specializes in one of those older technologies, you've got a pretty good niche."