Originally posted by @John Thedford:
I do know you can borrow money from a 401K. I believe the max is 50K and it has to be paid back within five years. The retirement plan guys can chime in with much better info. You possibly COULD convert to a Roth, but I believe you will have to pay the penalty. Once you have a Roth, all growth is tax free but you have to wait until you are an old man to take it out:)
John is mostly correct on the Roth IRA. If it's a regular IRA that you get a tax deduction for contributing to, moving it to a Roth would be taxable. The benefit is it would grow tax free. Converting to a Roth shouldn't create a penalty as it's still a conversion but the money has to stay in the Roth IRA and it is taxed as ordinary income. One other difference is that once that money has been contributed it can be taken back out later once you've had the account open for five years.
There are ways to take money out of a Roth IRA that are tax free. First time home buyers and higher education expenses are examples of ways to take earnings out that are tax free as well.