Opposite viewpoint: http://www.mrmoneymustache.com/
In general, just take (monthly spending) * 12 * [25 or 33] to get bounds on required savings. The only other useful observation is that reducing spending is much more effective for reaching financial independence than increasing earnings, and that most spending is staggeringly wasteful and easy to forgo.
Oh, and if you manage to find a life partner with the same values and earnings - congrats, you can easily retire within five years.
Retirement investment plans such as 401ks and IRAs have significant tax benefits. The catch is that they can't be withdrawn from before age 59 without huge penalties.
So if the goal is to retire early, one needs to use regular investment vehicles, which are subject to capital gains (15%),
An alternative is "substantially equal distributions" if I recall properly.
Once you own your place, you don't have to pay rent, you can live on $500 a month. That may be covered by the unemployment help, so you don't have to work either and don't pay taxes.
Bonus: if there is a spare room in your place, you can rent it and you'll make enough to cover a lot of expenses and save much money.
At least in Washington, unemployment is limited to I believe 26 weeks. IIRC, during the big downturn this was doubled in a lot of places (perhaps nationally?) but at least here it is back to 26 weeks.
Live extremely frugally, invest all savings in the S&P 500, live happily-ever-after on that same budget for the rest of your life.
IMO the key is being happy on a very small budget.