Mobilecast  program by Tea Vui Huang - the genius behind the iTunes synchronization tool for mobile phones, mobile tsunami detector and   putting Aibo on the cellphone, converts Podcasts into AMR files, splitting it into small 10 minute chunks automatically as Podcasts are downloaded by iPodder.

AMR files unlike MP3 files are much smaller (3-6 times) in size for the same playback time and the automatic 10 minute splits make it convenient to listen to the podcasts in parts. It's a free download from here. Also check out the TVH graphic calculator for mobile phones while you are there.