Jonathan Barber had already clocked up some 60 projects for 25 clients when Highams got him a berth at the Liverpool Victoria insurance group. "I was brought in to be responsible for a sizeable chunk of IT while Liverpool Victoria worked out what IT should look like," he says.

LV's IT had been outsourced to EDS but the UK's largest friendly society wanted dramatic business change and needed to know what kind of IT would best support that. One of the key questions, says Barber, was what sort of relationship with suppliers would suit the company -- in-house or third party. "We brought business engineering, design, strategy and governance in-house and opted for a third party for operational and development activities."

Barber stresses that interim managers need to be tactful. While he was working at savings company Skandia he was brought in over the company's senior IT director while he went off to design the future of the firm's IT.

"It's absolutely vital to be sensitive. If you take on difficult things it's hard not to upset people. But you have a duty to take the company forward; you have to look at what's best for the company. The most rewarding aspect is being able to make an impact quickly. The frustrating thing is not being there for the long term."

That may be true, but many interims go back to the same client or specialize in a particular industry. And since knowledge transfer is often a key objective in hiring an interim, they can at least have the satisfaction of having left a legacy behind.

David Miller, who has his own consultancy called ITDynamics, has worked a lot in the not-for-profit sector. Most recently he had a spell as IT transition manager for the crime reduction charity Nacro. The assignment involved replacing the entire IT department and recruiting new staff.

"In any situation there is a lot of leadership work to be done," he opines. "You have got to motivate people. At Nacro I had to create a new IT function and work with the people who were leaving. You can't do that if you abuse your position."

Tom Ganham, formerly at BT, is an interim who has worked in the public sector both at the Financial Services Authority and now at the Carbon Trust, a government agency tasked with publicizing carbon usage. At the Carbon Trust, Ganham has spent four-and-a-half months running IT after the previous CIO resigned.

"They haven't had a lot of continuity so I'm focusing on getting the IT right, setting up an IT steering committee. I've always been quite a restless person and although I get offered permanent positions I turn them down because I like doing this."

Although many interim CIOs take assignments with the largest organizations in the UK, not everyone likes to think big. Adrian Best worked for 10 years at pharmaceuticals giant GSK, but now spends his time helping small and medium-sized firms. "As companies grow they become more complex and multi-faceted," he says. "My job is to take out the cost of growth and help them get back to one process."

Best follows a formula he calls POST, standing for process, organization, system and technology. "Organizations tend to work in silos, so getting the process right is the first objective," he explains. "Technology is the last thing you put in place."

Interim CIOs, like Western gunslingers, might keep moving on, but demand for their services is unlikely to diminish. As long as there is trouble with IT, companies will be looking for a troubleshooter to come in and sort it out.