Having followed the fantastic podcasts, I recently decided to enroll at Fxphd. Its a pretty solid outfit and after a couple of weeks I can honestly say its living up to my expectations. I'm not really too interested in the 'nuts and bolts' of working a particular application (there are loads of tutorials for that) but rather the background to projects and industry best practice. If I pick up any gems I'll try to post them here but if you're interested in pushing your VFX skills forward I recommend you check out fxphd.