Anybody on HN actually doing a product that needs sat solvers? They're currently in vogue in software security; they solve search and reachability problems on modeled instruction streams.
It's not a product, but I've been doing some research that involves Bayesian inference. One recently developed technique (called weighted model counting) converts inference problems into SAT problems and the group I work with has been thinking about implementing this technique.
A lot of really smart people have worked on SAT, so a viable start to solving an NP-complete problem (e.g. traveling salesman in airline scheduling) is reduction to SAT.
They can also be used to do the actual optimizations. For example most formulations of the register allocation problem are NP-complete. SMT formulas can be used as a very powerful abstract domain in abstract interpretation.
I believe the actual intent of ``upvote == bookmark'' was to encourage users to upvote mostly stuff they actually believe worthy returning to, or saving for friends. Somebody out there correct me on that belief, please?