growacet,

To clarify. I think you meant that the RRSP is equal to the Individual Retirement Account (IRA) in the U.S. and not a 401K.  401K's are for large corporations of 50 employee's or greater and offer usually 10 - 14 mutual funds to invest in.

Self Direct IRA's allow the individual to tax shelter and invest in Mutual Funds or individual stocks.

Does the RRSP has a limit as to how much one can shelter each year?

 Also,  in the U.S. there is a ROTH IRA.  Fund with post tax dollars and as long as it is kept for five years, you get the distributions after 59 1/2 (age) tax free. Is there such a thing in Canada?

CD