1) Google Reader (Yes you can subscribe, organize, watch, and/or listen to your podcasts in Google Reader! I just discovered and it is way better than iTunes, watch out Apple)
2) Netvibes (Also webware)
3) iTunes (Good for finding podcasts but you need to download software and can't organize)
4) Juice (Freeware)
See also Wikipedia list (and definition) of Podcatchers
http://en.wikipedia.org/wiki/List_of_podcatchers
How Podcatchers Work