Mining bitcoin isn't worth it and has not been for quite some time (from a newbie perspective looking to jump in.) I did some Litecoin mining about 6 mos ago, and experimented with: a) firing up EC2 clusters with MIT StarCluster http://star.mit.edu/cluster/ (which is awesome for other reasons) b) buying my own rigs with expensive, high-end AMD GPUs. It was worth it for a while. I also pre-ordered some Butterfly Labs HW, but bailed on it when they couldn't produce a timely delivery.
tl;dr: it is fun for dorks like us, but at this point, don't expect to build your retirement nest egg mining -- just buying coins on an exchange is going to have a much better chance at ROI.
tl;dr: it is fun for dorks like us, but at this point, don't expect to build your retirement nest egg mining -- just buying coins on an exchange is going to have a much better chance at ROI.