I haven't taken a life drawing class in over 7 years and haven't been to a sitting in about 4. Visualizing people in various perspective is challenging, to say the least - when you're out of practice. I don't remember who recommended PoseManiacs to me, but it's been quite valuable as a learning tool and reference. Aside from just having a great library of 3D bodies (sans skin!), there's also warm up exercises, a hand viewer, a negative space viewer, and a perspective editor - all great tools to have in one single location.
Every now and again, I use this site for warm up or look up pose references if I can't do the pose myself.
It definitely doesn't replace the real deal, but it's an awesome alternative!
