The IRS allows victims of Ponzi schemes to deduct their losses as theft losses rather than as capital losses. While thefts of personal use property are currently barred (only disaster losses are allowed), thefts of investment property remain deductible as an itemized deduction. The IRS has guidance on determining the amount and timing of the losses as well as a safe harbor for determining the year in which the loss is deemed to occur.
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.