Sorry about your personal loss. The settlement is tax free to you because it is compensation for personal physical injury. However, if any part of the settlement is for punitive damages, those are taxable.
A retirement account to which up to $4,000 (or $5,000 if you are 50 or over) may be contributed for 2007, but deductions for the contribution are restricted if you are covered by a company retirement plan. Earnings accumulate tax free.