I was lucky enough to receive a lump sum of about 2-3 years wages when I took voluntary redundancy in April. I say lucky, well I had to work in an office-based corporate 'career' for 11 years to get it, but it gave me this opportunity and the knowledge of what I never want to do again, so luck comes in strange ways.
One of the books recommended on here - "Tunnel Visions" contains a couple of musings on this subject that I like - "How might a would-be honest man earn his living?...No-one intentionally sets out to be unaware of the consequences that their lifestyles have on their capacity to perceive reality, to think and feel as human beings rather than machines designed for the consumption of carefully manufactured and marketed 'needs'. However, what you spend a lot of time doing will have significant effects on you. Show me what a man spends his time doing and I will show you the man. Selecting work with this in mind seemed like a sound approach."
Currently I'm embarking on training to become a countryside/conservation warden - 2 days a week in college and 3 days volunteering, currently for the National Trust. It is and it isn't what I 'dreamed' about doing - I remember fleeting fantasies as a kid visiting National Trust properties on holidays and thinking how it might OK to spend one's time planting trees and driving about in a Land Rover, but for some reason it never translated into considering it as a job, until I started considering what I might do when the opportunity to ditch my last job came up last year.
As it turns out, it ticks many of the boxes of how I might want to make a living as a realistic proposition - outdoors, in the countryside, stress-free, feeling I am doing something positive in the world, working with people that are pretty much the opposite of the corporate go-getter. While I'm not actually employed at the moment, I see and do most what it involves on a day to day basis and what I see seems like something really decent for what one might call a 'job'. What sealed the deal was when I started waking up on Mondays feeling dread-free.
So I have 2-3 years before I finish my course and have to get a 'real' job and to be honest I'm the happiest I've been in years. Without trying to make it sound like 'fate' - I haven't really fulfilled a lifetime ambition or anything - what's interesting is how everything I have done in the last few years seems to have led me to it - my changes in values, questioning of things and realising what's important in life. I feel like it is a kind of enjoyable half-way house between not knowing what to do and having grand ambitions.
Another thing I realised recently - I have a friend who is now reasonably famous and successful after years of being skint, doing what he has always dreamed of doing - he couldn't be happier, but I wouldn't swap my life at the moment for his - so much of his time and life is not his own anymore, we (me and my friends) hardly see him and when we do it feels like our relationships have changed because of his success, a distance is there that wasn't before. Perhaps it's better not to get exactly what we wish for.

- Shipbuilder