We've got a new op amp tutorial using LTSpice, along with a neat little portable project: a mini guitar amp.
What started out as an introduction to operational amplifiers using LTSpice ended up becoming a two-day expense redesigning the LM386 Audio Amplifier -- on the transistor level -- and designing a tool for busking (a mini portable guitar amp). I did have fun building LM741 projects, getting into what the electrical characteristics listed on data sheets mean and learning how to replicate them in LTSpice. There's some information, a few projects, new tips for running simulations in LTSpice and a page full of fun resources to help you get started with op amps.
If you would like to see how easy it is to build a mini portable guitar amp, head over to the Introduction to Operational Amplifiers with LTSpice tutorial.