Russell Howard and Jon Richardson off 6 Music is usually good for a laugh. Nice and short, too. I also download the Russell Brand one. I know he's a bit 'marmite', but I find the radio show hilarious.
For gadgety fings the stuff.tv one are alright. They do video and an MP3 versions.
Radiohead have recently released a video podcast (basically a bunch of music videos) if you like that particular band. Get it on iTunes.
I don't really subscribe to any more!