You can also take your principal (and earnings) out of a traditional IRA penalty free if you work through the loopholes. http://www.madfientist.com/how-to-access-retirement-funds-ea...

This is info people should be aware of, but it doesn't help me if I only have money in a traditional IRA and want to use $100k for a down payment on a house.

Actually, I think buying a (first) house is one of the loopholes. From the linked article:

> "...you can withdraw retirement account money early to pay for education expenses, fund a first-time home purchase, ..."

Only up to $10k. I can withdraw $10k from my traditional IRA using that loophole, then a lot more from my roth.

If you decide to retire early you can always set up a Roth conversion ladder by rolling over IRAs and 401ks to Roth IRAs. It takes 5 years for those contributions to "season" so that you can take them out before 59.5, but you can take out capital gains that way as well. No need to contribute to a Roth today if that doesn't make sense otherwise.

Can you elaborate on this? I've been managing a post-tax account somewhat like a Roth IRA, though it is not an IRA because I plan to retire far before 59 1/2. I'm hoping for something in the middle of the two approaches with flexibility to withdraw early without penalty.

This is the most concise summary I've seen, but you can find some more discussion googling around for "Roth Conversion Ladder" - http://retireby40.org/roth-ira-conversion-ladder-minimize-ta...