Rock,
I think I figured out a way to do what you want to do - which is the same way that I use Itunes with my Ipod. (My Itunes libary was destroyed last year so I can no longer auto synch my Ipod as I would lose thousands of songs).
Funnily enough, I discovered this new way of manually moving podcasts while trying to figure out what cpragman was trying to say (I never could - he must be smarter than me, as I couldn't get his method to work).
1. Open up your Itunes in your regular Library view. Choose Pocasts from the left hand side (either in the sidebar if you have that enabled, or from the little "radio" icon if you don't.)
2. Mouse to the podcast you want to place on your Ipod.
3. Right-click it. A long menu will pop up.
4. Move to the "Add to Playlist" option. As you hover, all your playlists will be visible. But at the very top will be the name of your Ipod itself (whatever you named it originally). Choose THAT name, and voila! That podcast will now copy to your Ipod and be easily available when you disconnect.
A nice feature of this method is that you can shift-click several podcasts at once and do the same thing, and all your selected podcasts will copy over (if you're like me and update your Ipod only every few weeks).
Hope this helps - let me know if it works for you!