Rolling a 401(k) into an RRSP

Hi,
I have recently moved back to Canada from the US and I have a couple
questions about rolling a 401(k) into an RRSP (I know in general
this is not the best financial practice, but it looks like this
would be the best way for me to get access to the funds to use as
a down payment on a property).
1.  I know it's possible to roll and IRA into an RRSP.  Is it
    possible to do so with a 401(k).  From everybody I have talked to
    so far I am getting mixed signals as to whether this is possible,
    or I have to roll the 401(k) into an IRA first.
2.  What documentation, if any, do I need to show that I am rolling
    the 401(k), or the IRA, into an RRSP, so that it simply does
    not look like a contribution.
Thanks!
Dima
-- 
dima at cs.ubc.ca                                 http://www.cs.ubc.ca/~dima 
"The price of reliability is the pursuit of the utmost simplicity. 
 It is a price which the very rich find the most hard to pay." 
                                                 (Sir Antony Hoare, 1980)