Problem 497. Make an awesome ramp for a tiny motorcycle stuntman

Okay, given a vector, say v=[1 3 6 9 11], turn it into a matrix 'ramp' like so:

m=[1 3 6 9 11;
   3 6 9 11 0;
   6 9 11 0 0;
   9 11 0 0 0;
   11 0 0 0 0]

That way a tiny motorcycle stuntman can follow the trace and jump over 9 school buses safely.