I saved for ~18 months, then spent two years driving from Alaska to Argentina, because I wanted to.
I blogged the whole time at http://theroadchoseme.com
All the financial details are at http://theroadchoseme.com/the-price-of-adventure
You'll be interested to note I only spent $1200/mo on the road, which is almost exactly what I was spending month-to-month to go to work every day.
I'm currently back working as a Software Engineer, saving for the next adventure. This time I plan on saving up enough money, and maybe contracting a day every two weeks, that I can go traveling for at least 4-6 years next time. Current estimated departure is spring or fall 2014.
I'm extremely passionate about helping/encouraging other people to do the same thing. If you have any more questions, or I can help in any way, please don't hesitate to contact me (here, my blog, email, whatever)