I would also (fingers crossed) like the solution to work with R Sparse Matrices in the Matrix package.

>> A = [1,2,3,4,5]

A =

     1     2     3     4     5

>> B = [1;2;3;4;5]

B =

     1
     2
     3
     4
     5

>> bsxfun(@times, A, B)

ans =

     1     2     3     4     5
     2     4     6     8    10
     3     6     9    12    15
     4     8    12    16    20
     5    10    15    20    25

>> 

EDIT:

I would like to do a matrix multiplication of these sparse vectors, and return a sparse array:

> class(NRowSums)
[1] "dsparseVector"
attr(,"package")
[1] "Matrix"
> class(NColSums)
[1] "dsparseVector"
attr(,"package")
[1] "Matrix"
> 

NRowSums * NColSums (I think) w/o using a non-sparse variable to temporarily store data.