The new 2.2 system software for the iPhone allows you to download podcast episodes straight to the phone (previously it just copied episodes downloaded via iTunes if and when you synced with your home computer). This is great, but there are some problems with the process – namely that podcasts downloaded directly to the iPhone don’t show up in iTunes, so you need to delete them on the phone.
It isn’t immediately obvious (i.e. It’s completely hidden) how to do this – but it’s quite simple when you figure it out. In the iPod program, go to the list of episodes of podcasts, swipe your finger (as derisively as possible, of course) over the episode you want to get rid of – and the delete button will magically appear 🙂