In reply to goldmember:
If they have a shiny finish then cleaning with a brush and water, followed by applying the right colour polish will do the trick. If they're a suede or nubuck then you've got yourself a pair of very high maintenance shoes unless you just give in and convert them to a shiny finish by polishing. In my experience it is very hard to maintain the original finish of nubuck. You could try brushing the marks vigorously with a dry brush, if this takes away the stain then treat with a suede/nubuck waterproofing wax or spray. and brush up the nap.