With regards to the relevancy and a "catch all" resume..
I've been using a catch all for the past 6 years as a contractor and I've never been out of work more than a couple of weeks. I'm currently on contract number 9 and will be looking for my 10th soon.
Instead of paring the resume down to what the job is asking for, I've trimmed it down to what I want to do. Relevancy isn't just for the employer!
The IT job market, especially in the UK, is heavily controlled by the agencies. Having a universal CV/Resume means that when an agent calls me with a potential contract and I want to be put forward, as long as the agent has a recent copy in front of him I don't need to do anything. Alternatively if time is short and I need to get a CV to an agent by a set time then I don't have to think about it. I can spend 2 minutes firing an email off and then get back to whatever I was doing before.