extemporize
     v 1: manage in a makeshift way; do with whatever is at hand;
          "after the hurricane destroyed our house, we had to
          improvise for weeks" [syn: {improvise}]
     2: perform without preparation; "he extemporized a speech at
        the wedding" [syn: {improvise}, {improvize}, {ad-lib}, {extemporise}]
Source: WordNet® 2.0