I've written a bit about how I started as Guy In A Cubicle and eventually transitioned to Dotcom Thousandaire, running S3stat and Twiddla:

http://www.expatsoftware.com/articles/guy-on-the-beach-with-...

The short version is moving to Contracting, then Consulting Remotely, then Building Products while doing same, then learning how to Market them. With a good helping of Living Cheaply thrown in to keep the burn rate down.

It's a nice way to go about it, since you never need to worry about running out of money, and you can move at whatever speed you like since there's always a "day job" supplementing the product revenue.

Even better, since the business is built to run in the background while working elsewhere, once you turn off the "working elsewhere" part, you're effectively retired.