I recently read a study that showed most podcasters were males between 30-45 (guilty!) by a vast majority. Males overwhelmingly dominate the podcast-host market, but there are certainly women doing it.
Where are they all, you ask? They're right here on Amy Gahran's "Women in Podcasting" list.
I didn't count them all, but there's a pretty decent list there including podcasts, videocasts, and defunct shows as well.
The list is done in OPML which most browsers render as a traditional 'file tree' type of navigation system. An added advantage is that you can use your favourite reader or podcatcher to subscribe to the whole thing all at once.