If your earnings are more modest, you may be able to use an off-the-shelf "defined contribution" plan from a mutual fund company, broker, bank or insurance company.

FORBES: Self-Employment

We still believe that Vanguard is among the best mutual fund companies offering defined contribution plan investment management, recordkeeping and administrative services.

FORBES: More Worries for Defined Contribution Plan Fiduciaries (August 31, 2006)