We first played 3 of the covers and then promised to play another version for every pledge made. My favorite version has to be the B-52s style cover by The Rock Lobsters. This worked out rather well, and we received (throughout the course of the show) pledges for $75, $30, $10, $15, and incredibly enough, $250. Plus coupled with the fact that I pledged $100 and there was another $100 coincidentally pledged during the show (by another DJ's parents), we didn't wind up too shabbily.
To add to the confusion, two realaudio DJs apprenticed on the show... although they didn't get to do much, since all the pledgedrive stuff was going on. I promised them more opportunities next week.
The best part of all was getting to talk to the last lady who pledged. She said that she and her son listened every week, and that he always reminds her to turn on the radio for the show. Yeeee.