  We recast Grover's generalised search algorithm in a geometric language even
when the states are not approximately orthogonal. We provide a possible search
algorithm based on an arbitrary unitary transformation which can speed up the
steps still further. We discuss the lower and upper bounds on the transition
matrix elements when the unitary operator changes with time, thereby implying
that quantum search process can not be too fast or too slow. This is a
remarkable feature of quantum computation unlike classical one. Quantum
mechanical uncertainty relation puts bounds on search process. Also we mention
the problems of perturbation and other issues in time-dependent search
operation.
