That Google Listen is perfect. (Google have said it's still a bit of a work-in-progress.)

What I usually do is leave my phone to charge overnight and Google Listen generally downloads all the new podcasts over wifi, which are then waiting for me in the morning. What sometimes happens is that a download doesn't complete; it displays an error message and sometimes prevents downloading of podcasts further down the queue.

Therefore, I usually check the phone first thing in the morning -- if the above has happened, then just simply select the offending podcast and select Download from the menu; that usually does the trick. Even with the occasions when it doesn't sync first time, it's still preferable to fannying around with computers, cables and podcast clients. However, I would suggest also using a podcast client if you want to store your podcasts permanently (I think Google Listen only stores the last twenty).