Last week Burcin and I managed to bundle the first Psico package for calling Sage from within Singular!
The package itself is here:
http://sage.math.washington.edu/home/dreyer/spkg/psico-0.1.spkg
It needs he following modified Singular to be installed:
http://sage.math.washington.edu/home/dreyer/spkg/singular-3-1-1-4.psico.spkg
For the following example, Burcin also prepared some Singular sugar at
http://sage.math.washington.edu/home/dreyer/spkg/psicodemo.sing

LIB("psico.so");

factorint(15151515151515151515151515151515151515151515);
// [(3, 1), (5, 1), (11, 1), (23, 1), (89, 1), (101, 1), (4093, 1), (8779, 1), (21649, 1), (513239, 1), (1052788969, 1), (1056689261, 1)]
def m = sagematrix("QQ",2,2);
m;

// [0 0]
// [0 0]
setitem(m, 0,1, 5);
setitem(m, 1,1, 17);
m;

// [ 0  5]
// [ 0 17]
m*m;
// [  0  85]
// [  0 289]
m+m;
// [ 0 10]
// [ 0 34]
minimal_poly(m);
// x^2 - 17*x
def h = make_parallel("prime", 2);
def r = h(list(123,234,345,456));
gen2list(r);

// [(((123,), {}), 113), (((234,), {}), 233), (((345,), {}), 337), (((456,), {}), 449)]